Search

Background A phase 2 randomized-controlled safety and immunogenicity trial evaluating different doses of recombinant acellular pertussis vaccine containing genetically-inactivated pertussis toxin (PTgen) was conducted in women of childbearing age in Thailand to identify formulations to advance to a trial in pregnant women. Methods A total of 250 women were randomized 1:1:1:1:1 to receive one dose of one of three investigational vaccines including low-dose recombinant pertussis-only vaccine containing 1 μg PTgen and 1 μg FHA (ap1gen), tetanus, reduced-dose diphtheria (Td) combined to ap1gen (Tdap1gen) or combined to recombinant pertussis containing 2 μg PTgen and 5 μg FHA (Tdap2gen), or one dose of licensed recombinant TdaP vaccine containing 5 μg PTgen and 5 μg FHA (Boostagen®, TdaP5gen) or licensed Tdap vaccine containing 8 μg of chemically inactivated pertussis toxoid (PTchem), 8 μg FHA, and 2.5 μg pertactin (PRN) (BoostrixTM, Tdap8chem). Serum Immunoglobulin G (IgG) antibodies against vaccine antigens were measured before and 28 days after vaccination by ELISA. To advance to a trial in pregnant women, formulations had to induce a PT-IgG seroresponse rate with a 95% confidence interval (95% CI) lower limit of ≥ 50%. Results Between 5 and 22 July 2018, a total of 250 women with median age of 31 years were enrolled. Post-vaccination PT-IgG seroresponse rates were 92% (95% CI 81–98) for ap1gen, 88% (95% CI 76–95) for Tdap1gen, 80% (95% CI 66–90) for Tdap2gen, 94% (95% CI 83–99) for TdaP5gen, and 78% (95% CI 64–88) for Tdap8chem. Frequencies of injection site and systemic reactions were comparable between the groups. No serious adverse events were reported during the 28-day post-vaccination period. Conclusions All recombinant acellular pertussis vaccines were safe and immunogenic in women of childbearing age, and all met pre-defined immunogenicity criteria to advance to a trial in pregnant women. Clinical Trial Registration: Thai Clinical Trial Registry, TCTR20180321004.

Background Cervical cancer is a leading cause of cancer-associated mortality among women in India, with 96,922 new cases and 60,078 deaths each year, almost one-fifth of the global burden. In 2018, Sikkim state in India introduced human papillomavirus (HPV) vaccine for 9–13-year-old girls, primarily through school-based vaccination, targeting approximately 25,000 girls. We documented the program’s decision-making and implementation processes. Methods We conducted a post-introduction evaluation in 2019, concurrent with the second dose campaign, by interviewing key stakeholders (state, district, and local level), reviewing planning documents, and observing cold chain sites in two purposefully-sampled community areas in each of the four districts of Sikkim. Using standard questionnaires, we interviewed health and education officials, school personnel, health workers, community leaders, and age-eligible girls on program decision-making, planning, training, vaccine delivery, logistics, and communication. Results We conducted 279 interviews and 29 observations in eight community areas across four districts of Sikkim. Based on reported administrative data, Sikkim achieved >95% HPV vaccination coverage among targeted girls for both doses via two campaigns; no severe adverse events were reported. HPV vaccination was well accepted by all stakeholders; minimal refusal was reported. Factors identified for successful vaccine introduction included strong political commitment, statewide mandatory school enrollment, collaboration between health and education departments at all levels, and robust social mobilization strategies. Conclusions Sikkim successfully introduced the HPV vaccine to multiple-age cohorts of girls via school-based vaccination, demonstrating a model that could be replicated in other regions in India or similar low- and middle-income country settings.

BackgroundThe Receptor Binding Domain (RBD) of the SARS-CoV-2 spike protein is the target for many COVID-19 vaccines. Here we report results for phase 1 clinical trial of two COVID-19 vaccine candidates based on recombinant dimeric RBD (d-RBD).MethodsWe performed a randomized, double-blind, phase I clinical trial in the National Centre of Toxicology in Havana. Sixty Cuban volunteers aged 19-59 years were randomized into three groups (20 subjects each): 1) FINLAY-FR-1 (50 mcg d-RBD plus outer membrane vesicles from N. meningitidis); 2) FINLAY-FR-1A-50 mcg d-RBD (three doses); 3) FINLAY-FR-1A-25 mcg d-RDB (three doses). The FINLAY-FR-1 group was randomly divided to receive a third dose of the same vaccine candidate (homologous schedule) or of FINLAY-FR-1A-50 (heterologous schedule). The primary outcomes were safety and reactogenicity. The secondary outcome was vaccine immunogenicity. Humoral response at baseline and following each vaccination was evaluated using live-virus neutralization test, anti-RBD IgG ELISA and in-vitro neutralization test of RBD:hACE2 interaction.ResultsMost adverse events were of mild intensity (63.5%), solicited (58.8%), and local (61.8%); 69.4% with causal association with vaccination. Serious adverse events were not found. The FINLAY-FR-1 group reported more adverse events than the other two groups. After the third dose, anti-RBD seroconversion was 100%, 94.4% and 90% for the FINLAY-FR-1, FINLAY-FR-1A-50 and FINLAY-FR-1A-25 respectively. The in-vitro inhibition of RBD:hACE2 interaction increased after the second dose in all formulations. The geometric mean neutralizing titres after the third dose rose significantly in the group vaccinated with FINLAY-FR-1 with respect to the other formulations and the COVID-19 Convalescent Serum Panel. No differences were found between FINLAY-FR-1 homologous or heterologous schedules.ConclusionsVaccine candidates were safe and immunogenic, and induced live-virus neutralizing antibodies against SARS-CoV-2. The highest values were obtained when outer membrane vesicles were used as adjuvant.Trial registryhttps://rpcec.sld.cu/en/trials/RPCEC00000338-En

Background Pneumococcal conjugate vaccines (PCVs) have greatly reduced the incidence of pneumococcal disease, yet unmet medical need remains due to increased disease caused by non-vaccine serotypes (STs). V114 (VAXNEUVANCETM, Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA) is a 15-valent PCV containing 13 serotypes in licensed PCV13 and 2 additional serotypes (22F, 33F) which significantly contribute to pneumococcal disease burden. This phase 3 trial compared safety, tolerability, and immunogenicity of V114 to PCV13 in adults ≥50 years of age. Methods Adults were randomized 1:1 to receive a single dose of V114 or PCV13; randomization was stratified by age (50–64 years, 65–74 years, and ≥75 years). Adverse events (AEs) were collected following vaccination. Serotype-specific opsonophagocytic activity (OPA) and immunoglobulin G (IgG) antibodies were measured prior to and 30 days after vaccination (Day 30). Primary objectives included assessing noninferiority of V114 to PCV13 for the 13 shared serotypes and superiority of V114 to PCV13 for the two unique serotypes. Superiority of V114 to PCV13 for shared serotype 3 was assessed as a secondary objective. Results Overall, 1,202 participants were vaccinated (V114 N = 602, PCV13 N = 600). The most commonly reported AEs across both groups were injection-site pain, fatigue, and myalgia. V114 met noninferiority criteria compared to PCV13 for the 13 shared serotypes (using a 2-fold non-inferiority margin for the ratio of OPA geometric mean titers [GMTs] [V114/PCV13] at Day 30) and met superiority for the 2 unique serotypes (using a 2-fold super-superiority margin for the ratio of OPA GMTs [V114/PCV13] at Day 30 and a 0.10 super-superiority margin for the difference in proportions of participants with ≥4-fold rise from prevaccination to Day 30). V114 met superiority criteria compared to PCV13 for serotype 3 (based on a super-superiority margin of 1.2 for the ratio of the OPA GMTs [V114/PCV13] and a superiority margin of 0 for the difference in proportions of participants with ≥4-fold rise). [NCT03950622, EudraCT#2018-004316-22, Japic-CTI#194845].

Thrombosis and Thromobocytopenia Syndrome (TTS) has been associated with the AstraZencea (AZ) COVID-19 vaccine. Australia has reported low TTS incidence of 3000 deaths prevented under high transmission. Risks versus benefits varied significantly between age groups and transmission levels. Under high transmission, deaths prevented by AZ vaccine far exceed deaths from TTS (by 8 to >4500 times depending on age). Probability of dying from COVID-related atypical severe blood clots was 58-126 times higher (depending on age and sex) than dying from TTS. To our knowledge, this is the first example of the use of Bayesian networks for risk-benefit analysis for a COVID-19 vaccine. The model can be rapidly updated to incorporate new data, adapted for other countries, extended to other outcomes (e.g., severe disease), or used for other vaccines.HIGHLIGHTSAZ vaccination risk-benefit analysis must consider age/community transmission levelAZ vaccine benefits far outweigh risks in older age groups and during high transmissionAZ vaccine-associated TTS lower fatality than COVID-related atypical blood clotsBayesian networks utility for risk-benefit analysis of rapidly evolving situationsBNs allow integrating multiple data sources when large datasets are not available

Background The measles-mumps-rubella vaccine was withdrawn from the National Immunization Program in 1993 because aseptic meningitis was reported as a post-vaccination adverse reaction in Japan. This study aimed to measure the uptake of and determinants influencing mumps vaccination, including concerns about adverse reactions. Methods We conducted this cross-sectional survey for all parents whose children underwent 18-month health checkups in Kanazawa City between October 2019 and February 2020. Community nurses interviewed the parents using a unified questionnaire, and 1422 parents responded. Results Based on records from maternal and child health handbooks, the mumps vaccination rate was 55.6%. The most common reason for parents not vaccinating their children against mumps was that “it is not a routine vaccine” (35.9%), whereas “concern about adverse reactions” accounted for only 2.2%. In multivariate analysis, the significantly positive factors associated with vaccination against mumps were children whose parents knew that adverse reactions were fever, rash, diarrhea, and vomiting; had received a recommendation for vaccination from their family members; had read the Vaccination Guide issued by the city; vaccinated with other voluntary vaccines or treated for gastroenteritis; and had a deep general understanding of vaccination. Conversely, the significantly negative factor was children whose parents had not received any recommendation for vaccination. Conclusion The mumps vaccination rate could be improved by adding the mumps vaccine in the routine vaccination program and educating parents by disseminating correct information on mumps and the mumps vaccine, and by primary care physicians routinely recommending vaccination.

The Biological E inactivated hepatitis A (HAPIBEV™) vaccine was developed by importing the Healive® vaccine bulk from China and fill-finish it in India. Healive® vaccine is approved in China for both children and adults. This study assessed the safety and immunogenicity of HAPIBEV™ vaccine as compared to the Havrix 720® vaccine of GlaxoSmithKline (GSK) pharmaceuticals when administered intramuscularly (IM) 6 months apart in 1–15 years old hepatitis A virus (HAV) vaccine naive children in India. This Phase 3, single blind, parallel, randomized, active-controlled, two-arm study was conducted at 8 centers in India in healthy HAV vaccine–naive children. Subjects were stratified into 2 age subsets (1–7 and 8–15 years) and randomly assigned to either BE-HAPIBEV™ or GSK’s Havrix® vaccine and administered 2 IM injections 6 months apart. The immunogenicity evaluations included: (1) proportion of subjects who achieved the following at Day 210 from baseline: (a) seroconversion (≥20 mIU/mL) with anti-HAV immunoglobulin G (IgG) antibodies, (b) ≥4-fold increase in anti-HAV IgG antibodies, and (c) ≥2-fold increase in anti-HAV IgG antibodies concentration who were already seroconverted at baseline and (2) geometric mean concentrations (GMC) of anti-HAV IgG antibodies at baseline and Day 210. Safety was evaluated throughout the study. A total of 467 (89.8%) subjects completed the study. The non-inferiority criterion was met by HAPIBEV™ vaccine as seroconversion rates in both vaccine groups were 100%. Overall, other immunogenicity evaluations were either similar in both vaccine groups or higher in the HAPIBEV™ group compared with the Havrix® group. The safety profile was also comparable between HAPIBEV™ and Havrix® groups. The most common adverse event (AE) was injection site pain, and the majority of AEs were mild in severity. The HAPIBEV™ vaccine demonstrated an immunological and safety profile on par with Havrix® in 1–15 years old healthy HAV vaccine-naive Indian children. This study is registered with clinical trial registry of India bearing no: CTRI/2019/04/018384 on 02 Apr 2019.

Emerging evidence suggest a possible association between immune thrombocytopenia (ITP) and some formulations of COVID-19 vaccine. We conducted a retrospective case series of ITP following vaccination with Vaxzevria ChadOx1-S (AstraZeneca) and mRNA Comirnaty BNT162b2 COVID-19 (Pfizer-BioNTech) vaccines and compare the incidence to expected background rates for Victoria during the first six months of the Australian COVID-19 vaccination roll-out in 2021. Cases were identified by reports to the Victorian state vaccine safety service, SAEFVIC, of individuals aged 18 years or older presenting with thrombocytopenia following COVID-19 vaccination without evidence of thrombosis. Twenty-one confirmed or probable cases of ITP were identified following receipt of AstraZeneca (n = 17) or Pfizer-BioNTech (n = 4) vaccines. This translates to an observed incidence of 8 per million doses for AstraZeneca vaccine, twice the expected background rate of 4.1 per million. The observed rate for Pfizer-BioNTech was consistent with the expected background rate. The median time to onset for the cases post AstraZeneca vaccination was 10 days (range 1–78) and median platelet nadir 5 × 109/L (range 0–67 × 109/L). Hospital presentations or admissions for management of symptoms such as bleeding occurred in 18 (86%) of the cases. The majority of cases (n = 11) required intervention with at least 2 therapy modalities. In conclusion, we observed a substantially higher than expected rate of ITP following AstraZeneca vaccination. ITP is the second haematological adverse event, distinct from that of thrombosis with thrombocytopenia syndrome (TTS), observed following AstraZeneca vaccination.

Background Streptococcus pneumoniae causes pneumococcal disease, and older adults are at an increased risk. Sequential vaccination of 13-valent pneumococcal conjugate vaccine (PCV13) followed by 23-valent pneumococcal polysaccharide vaccine (PPSV23) is recommended for broad protection against pneumococcal disease in some countries. Methods This phase III trial evaluated the safety, tolerability, and immunogenicity of sequential administration of either V114 (a 15-valent PCV containing serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, 22F, 23F, and 33F) or PCV13, followed 12 months later by PPSV23, in healthy adults aged ≥50 years (NCT03480763). A total of 652 participants were randomized 1:1 to receive either V114 or PCV13, followed by PPSV23. Results The most common solicited adverse events (AEs) following PCV vaccination included injection-site pain and fatigue. Higher proportions of participants with these events were observed in the V114 group following PCV; however, these differences were not clinically significant. Following PPSV23 vaccination, the most common solicited AEs were injection-site pain and injection-site swelling; the proportions of participants with these events were comparable between both groups. Incidence of serious AEs was low in both groups following PCV and PPSV23, and none were related to study vaccines. No deaths occurred during the study. Serum opsonophagocytic activity geometric mean titers and immunoglobulin G geometric mean concentrations were comparable between both groups for all 15 serotypes in V114 following PPSV23. Immune responses elicited by V114 persisted for at least 12 months. Immune responses at 30 days and 12 months post-vaccination with PCV were comparable between both groups for the 13 shared serotypes and higher in the V114 group for the V114-unique serotypes (22F and 33F). Conclusion Administration of V114 followed by PPSV23 was well tolerated and induced comparable antibody levels to PCV13 followed by PPSV23 in healthy adults aged ≥50 years.

Background The WHO declared COVID-19 a pandemic on March 11th, 2020. This serious outbreak and the precipitously increasing numbers of deaths worldwide necessitated the urgent need to develop an effective severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine. The development of COVID-19 vaccines has moved quickly. In this study, we assessed the efficacy, safety, and immunogenicity of an inactivated (SARS-CoV-2) vaccine. Methods We conducted a randomized, double-blind, placebo-controlled trial to evaluate the efficacy, immunogenicity, and safety of an inactivated SARS-CoV-2 vaccine and its lot-to-lot consistency. A total of 1620 healthy adults aged 18-59 years were randomly assigned to receive 2 injections of the trial vaccine or placebo on a day 0 and 14 schedule. This article was based on an interim report completed within 3 months following the last dose of study vaccine. The interim analysis includes safety and immunogenicity data for 540 participants in the immunogenicity subset and an efficacy analysis of the 1620 subjects. For the safety evaluation, solicited and unsolicited adverse events were collected after the first and second vaccination within 14 and 28 days, respectively. Blood samples were collected for an antibody assay before and 14 days following the second dose. Results Most of the adverse reactions were in the solicited category and were mild in severity. Pain at the injection site was the most frequently reported symptom. Antibody IgG titer determined by enzyme-linked immunosorbent assay was 97.48% for the seroconversion rate. Using a neutralization assay, the seroconversion rate was 87.15%. The efficacy in preventing symptomatic confirmed cases of COVID-19 occurring at least 14 days after the second dose of vaccine using an incidence rate was 65.30%. Conclusions From the 3-month interim analysis, the vaccine exhibited a 65.30% efficacy at preventing COVID-19 illness with favorable safety and immunogenicity profiles.

Background COVID-19 vaccines have been speedily developed and deployed. The more vaccine doses are delivered to users, the more common adverse events following immunization (AEFI) are reported. This study aimed to identify factors affecting AEFI in Vietnamese people receiving the COVID-19 vaccine AZD1222 developed by AstraZeneca and Oxford University. Methods In July 2021, an online cross-sectional survey was conducted among Vietnamese who have been vaccinated with COVID-19 vaccines. The questionnaire collected demographic characteristics, medical history, types of injected vaccines, common AEFI, and post-vaccination activities from respondents. The effects of host-related factors on AEFI including 24 specific symptoms were also explored. Results After screening, 1028 participants who were Vietnamese, over 18 years old and received at least one dose of AZD1222, were included in the study. Only 40/1028 (3.9%) participants reported not having any AEFI, whereas 25/1028 (2.4%) reported to have severe symptoms. The most common AEFI were moderate fever (69.4%), muscle aches (68.6%), followed by fatigue/ sleepiness (62.5%), body aches (59.4%), headache (58.5%), pain at injection site (58.3%) and chills (45.7%). Data analysis showed that females complained about AEFI particularly gastrointestinal symptoms more frequently than males. Age of participants and number of doses were also important factors affecting AEFI as the increase of age or number of vaccine doses was associated with the decrease of self-reported AEFI frequency. Conclusions This study provides a detailed assessment of risk factors associated with AEFI in Vietnamese people vaccinated with AZD1222. It seems that gender, age and vaccine doses are important factors affecting AEFI.

Previous studies have indicated that girls experiencing suspected adverse events (AE) following HPV vaccination were more vulnerable prior to vaccination. However, no study has previously investigated differences in vulnerability using prospectively collected self-reported measures of vulnerability. The objective of this study therefore was to describe the distribution of biological and psychosocial indicators of vulnerability in girls referred to a hospital setting due to suspected adverse events and compare it with a sample of non-referred HPV vaccinated girls. The study was conducted as a case control study based within the Danish National Birth Cohort. Cases were defined as HPV vaccinated girls referred to a hospital setting between 2015 and 2017 due to suspected adverse events (n = 80), and 5 controls were randomly selected from the remaining source population, matched to cases on age at vaccination, region of residence and year of vaccination. The final study population consisted of 480 girls. Prior exposures were based on information gathered from an 11 year follow up of the DNBC and included information on self-rated health, frequent health complaints, medication use, bullying, stressful life events and physical activity. Conditional logistic regression analysis was used to estimate the association between each exposure and referral. The percentage of individuals in the exposed category of each exposure was generally higher for cases than controls. Particularly, the odds of being referred were higher for those with low self-rated health compared to high (OR [95%-CI] 2.43 [1.07–5.5]1), those being bullied (OR 3.19 [1.17–8.73]), and those who had taken medication (OR 2.22 [1.32–3.67]). Overall, these results indicated that girls experiencing suspected AE following HPV vaccination were more vulnerable prior to vaccination.

Background We assessed the humoral immune response of both ChAdOx1-nCOV (CovishieldTM) and BBV-152 (CovaxinTM) vaccines in Indian health care workers (HCW). Methods A Pan-India, Cross-sectional, Coronavirus Vaccine-induced Antibody Titre (COVAT) study was conducted that measured SARS-CoV-2 anti-spike binding antibody quantitatively, 21 days or more after the first and second dose of two vaccines in both severe acute respiratory syndrome (SARS-CoV-2) naive and recovered HCW. Primary aim was to analyze antibody response (seropositivity rate, Geometric Mean Titre [GMT] and 95% Confidence Interval [CI]) following each dose of both vaccines and its correlation to age, sex, blood group, body mass index (BMI) and comorbidities. Here we report the results of anti-spike antibody response after first and two completed doses. Results Among the 515 HCW (305 Male, 210 Female) who took two doses of both vaccines, 95.0% showed seropositivity to anti-spike antibody. However, both seropositivity rate and GMT (95% CI) of anti-spike antibody was significantly higher in Covishield vs. Covaxin recipients (98.1 vs. 80.0%; 129.3 vs. 48.3 AU/mL; both p 60-years, males, people with any comorbidities, and history of hypertension (HTN) had a significantly less anti-spike antibody GMT compared to age ≤ 60 years, females, no comorbidities and no HTN respectively, after the completion of two doses of either vaccine. Gender, presence of comorbidities, and vaccine type were independent predictors of antibody seropositivity rate and anti-spike antibody titre levels in multiple logistic and log transformed linear regression analysis. Both vaccine recipients had similar solicited mild to moderate adverse events and none had severe or unsolicited side effects. Conclusions Both vaccines elicited good immune response after two doses, although seropositivity rates and GMT of anti-spike antibody titre was significantly higher in Covishield compared to Covaxin recipients.

Background: The currently licensed quadrivalent MenACWY-CRM conjugate vaccine presentation consists of two vials (lyophilised MenA and liquid MenCWY) to be reconstituted before injection. A new fully liquid formulation in a single vial has been developed to further improve the vaccine presentation. Since the MenA structure is subject to hydrolytic degradation, this study was conducted to compare the immunogenicity and safety of the investigational MenACWY-CRM liquid vaccine with the licensed vaccine. Methods: In this multicentre, randomised, controlled, observer-blind, phase 2b study, 979 healthy adults were administered a single dose of MenACWY-CRM liquid presentation or the currently licensed MenACWY-CRM vaccine. MenA free saccharide generation was accelerated to approximately 30% in the liquid presentation and MenA polysaccharide O-acetylation was reduced to approximately 40%, according to a controlled procedure. Immunological non-inferiority of the MenACWY-CRM liquid to the licensed vaccine, as measured by human serum bactericidal assay (hSBA) geometric mean titres (GMTs) against MenA 1 month post-vaccination, was the primary study objective. Safety assessment was among the secondary objectives. Results: Immune responses against each serogroup were similar between the two vaccine groups and was non-inferior for MenA. Adjusted hSBA GMTs for MenA were 185.16 and 211.33 for the MenACWY-CRM liquid presentation and currently licensed vaccine presentation, respectively. The between-group ratio of hSBA GMTs for MenA was 0.88, with a two-sided 95% confidence interval lower limit of 0.64, greater than the prespecified non-inferiority margin of 0.5, thus meeting the primary study objective. Both vaccines were well tolerated. No serious adverse events were considered related to vaccination. Conclusions: The levels of MenA free saccharide and polysaccharide O-acetylation did not affect the immunogenicity of the fully liquid presentation, which was demonstrated to be non-inferior to the immunogenicity of the currently licensed MenACWY-CRM vaccine against MenA. The immunogenicity, reactogenicity and safety profiles of the two vaccine presentations were similar. (c) 2021 GlaxoSmithKline Biologicals S.A. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Px563L is a next-generation anthrax vaccine candidate consisting of a protein subunit, mutant recombinant protective antigen SNKE167-ΔFF-315-E308D (mrPA), and liposome-embedded monophosphoryl lipid A (MPLA) adjuvant. Px563L has the potential to deliver an improved safety and immunogenicity profile relative to the currently licensed vaccine, which is produced from filtered B. anthracis culture supernatants. We conducted a Phase 1, double–blind, placebo–controlled, dose–escalation study in 54 healthy subjects to evaluate Px563L at 3 dose levels of mrPA (10, 50, and 80 mcg). For each dose level, 18 subjects were randomized in an 8:8:2 ratio to Px563L (mrPA with adjuvant), RPA563 (mrPA only) or placebo (saline). Each subject received an intramuscular (IM) injection on Day 0 and Day 28. Primary safety and immunogenicity analysis was conducted after all subjects completed the Day 70 visit, a duration deemed clinically relevant for post-exposure prophylaxis. Long-term safety was assessed through Day 393. Vaccinations with Px563L at all dose levels were well-tolerated. There were no serious adverse events or adverse events (AE) leading to early withdrawal. In all treatment groups, most AEs were due to injection site reactions, and all AEs at the 10 and 50 mcg dose levels were mild. For the primary immunogenicity endpoint (protective toxin neutralizing antibody 50% neutralization factor [TNA NF50]), titers started to increase significantly after the second administration of Px563L, from Day 35 through Day 70, with the geometric mean and lower bound of the 95% confidence interval exceeding 0.56, a threshold correlating with significant survival in animal models of anthrax exposure. In conclusion, Px563L, administered as two IM doses 28 days apart, was well-tolerated and elicited a protective antibody response starting at seven days after the second vaccination. These findings support the continued development of Px563L in a two-dose regimen for anthrax post-exposure prophylaxis. ClinicalTrials.gov identifier NCT02655549.

IMPORTANCE Passive surveillance systems are susceptible to the under-reporting of adverse events (AE) and a lack of information pertaining to vaccinated populations. Conventional active surveillance focuses on predefined AEs. Advanced data mining tools could be used to identify unusual clusters of potential AEs after vaccination. OBJECTIVE To assess the feasibility of a novel tree-based statistical approach to the identification of AE clustering following the implementation of a varicella vaccination program among one-year-olds. SETTING AND PARTICIPANTS This nationwide safety surveillance was based on data from the Taiwan National Health Insurance database and National Immunization Information System for the period 2004 through 2014. The study population was children aged 12-35 months who received the varicella vaccine. EXPOSURE First-dose varicella vaccine. OUTCOMES AND MEASURES All incident ICD-9-CM diagnoses (emergency or inpatient departments) occurring 1-56 days after the varicella vaccination were classified within a hierarchical system of diagnosis categories using Multi-Level Clinical Classifications Software. A self-controlled tree-temporal data mining tool was then used to explore the incidence of AE clustering with a variety of potential risk intervals. The comparison interval consisted of days in the 56-day follow-up period that fell outside the risk interval. RESULTS Among 1,194,189 varicella vaccinees with no other same-day vaccinations, nine diagnoses with clustering features were categorized into four safety signals: fever on days 1-6 (attributable risk [AR] 38.5 per 100,000, p

Background Two phase 1/phase 2 studies assessed 2 formulations of investigational bivalent Clostridioides (Clostridium) difficile vaccine (QS-21 adjuvanted toxoid and toxoid-alone) in healthy adults 50–85 years of age. Methods The QS-21 adjuvanted toxoid vaccine study randomized subjects 3:1 to 100 μg QS-21–containing C difficile vaccine or placebo administered in a shortened-month (Months 0, 1, 3) or day (Days 1, 8, 30) regimen. The toxoid-alone vaccine study randomized subjects 3:3:1 to receive 100 or 200 μg unadjuvanted C difficile vaccine formulation or placebo in Stages 1 and 2 (sentinel cohorts of different age groups), and 3:1 to receive the selected dose of unadjuvanted C difficile vaccine formulation or placebo in Stage 3 (Days 1, 8, 30). Safety was the primary outcome for both studies. Immunogenicity was determined by measuring serum toxin A– and B–specific neutralizing antibodies. Results In the day regimen, 10 reports across both studies of grade 3 injection site redness postdose 2 triggered predefined stopping rules. Local reactions in both studies were more common among vaccine versus placebo recipients. Injection site pain predominated and was generally mild in severity. Systemic events were infrequent and generally mild-to-moderate in severity. Adverse events were reported by 50.0%–75.0% and 16.7%–50.0% of subjects in the QS-21 and toxoid-alone studies, respectively. Immune responses peaked around Day 37 (shortened-month regimen) or between Day 15 and Month 2 (day regimen) and remained above baseline throughout follow-up. Conclusions Both formulations demonstrated robust immunogenicity. Both studies stopped early due to grade 3 injection site redness postdose 2 of the day regimen; neither formulation progressed to later stage development. Instead, an aluminum hydroxide-containing formulation of the vaccine candidate administered at 0, 1, and 6 months, which was safe and immunogenic in phase 1 and 2 studies, advanced to phase 3 studies.

BACKGROUND: In 2010, the Australian seasonal influenza vaccination program for children under 5 years of age was suspended due to an unexpected increase in fever and febrile convulsions causally associated with one particular influenza vaccine brand. A subsequent national review made seven recommendations to improve vaccine pharmacovigilance. Ten years on, in advance of implementing the COVID-19 immunisation program, we evaluated views on the capacity of Australia's vaccine pharmacovigilance system to promptly detect, examine and communicate a signal. METHODS: Semi-structured interviews were conducted between July and October 2020 with individuals with expertise in vaccine safety in Australia using an interview guide informed by key Australian and international frameworks. Interviews were digitally recorded and transcribed verbatim. Thematic analysis was used to code data using a deductive approach. RESULTS: Interviews with seventeen participants enabled six themes to be identified. Participants described improvement and significant innovation within Australia's vaccine pharmacovigilance system over the decade since 2010, particularly through establishment of a new active, cohort event monitoring system using short message service surveys. Participants thought Australia had a good foundation for COVID-19 vaccine safety surveillance; implementation of the COVID-19 immunisation program was seen as a potential driver for ongoing enhancement through: a) improved integration of the active surveillance and spontaneous reporting systems, and; b) development of population-level active surveillance, including through data linkage. Transparent communication was considered essential to address the unprecedented challenges of COVID-19 and broader vaccine safety concerns. CONCLUSIONS: Vaccine safety experts in Australia convey confidence in the innovative pharmacovigilance systems implemented over the past 10 years. While Australia has a multifaceted system incorporating both active surveillance and spontaneous reporting systems, COVID-19 vaccine implementation represents an opportunity to enhance current systems and to develop new, systematic approaches to vaccine pharmacovigilance that should make both a local and global contribution.

INTRODUCTION: COVID-19 vaccination seems to be the most pertinent pharmacologic public health measure to control the pandemic. Reactogenicity symptoms were frequent in vaccine recipients mostly mild to moderate and commonly reported after the second dose. However, there is a lack of data in patients with a previous diagnosis of Covid-19. METHODS: We analysed side effects of 311 patients after the first dose of Pfizer-BioNTech COVID-19 vaccine, in a french university hospital. We compared patients with COVID-19 history to naive individuals. All the data collected are based on self-reported, including COVID-19 exposure status. RESULTS: Overall, 229 (74%) patients reported at least one side effect. Among participants with history of Covid-19, 95% reported at least one adverse event versus 70% in naive patients (p

Background Maternal immunization has the potential to reduce both maternal and infant morbidity and mortality by protecting women from complications during pregnancy as well as conferring protection for babies who are too young to be vaccinated. Limited evidence is available about the drivers of maternal immunization in middle-income countries such as Peru. Vaccines against tetanus, diphtheria and influenza are recommended beginning in the second trimester in Peru; however, vaccination coverage has remained low in Peru compared to other countries in the region. As additional vaccines are recommended for administration in pregnancy, a better understanding of the perceptions and attitudes of pregnant women that influence vaccination are needed to design communication materials. Methods We conducted an exploratory qualitative study to understand the individual level factors influencing pregnant women’s vaccine uptake. We interviewed pregnant women about their knowledge, perceptions and experiences with vaccination during pregnancy. Community health workers recruited women in a peri urban area of Peru in April 2018. Results Twelve women were interviewed, the majority of which had received vaccination during the current pregnancy. The most common reasons for vaccination were to protect the baby and because vaccines are effective. Concerns included vaccine safety during pregnancy and adverse effects on the unborn baby. Some women mentioned that because vaccines are given later in pregnancy, the unborn baby is stronger, so vaccines will not harm them. Women highlighted that the main reason for not being vaccinated was lack of information. They also noted that they were the decision-maker in whether or not they were vaccinated. Most women said that they trusted healthcare providers and that trust was linked to providing information through open communication. Conclusions Overall, participants were supportive of maternal vaccination. They believed that vaccines were effective in protecting both their unborn baby and themselves. The main reason given for non-vaccination was lack of knowledge about vaccination in pregnancy. The strong desire expressed by study participants to get more information presents an opportunity for immunization programs to develop interventions that facilitate better information dissemination to pregnant women to increase vaccination uptake.

BACKGROUND: Despite safe and effective WHO prequalified rotavirus vaccines, at least 84 million children remain unvaccinated. A birth dose schedule of the RV3-BB vaccine was reported to be highly efficacious against severe rotavirus disease in Indonesian infants and is under further development at PT Bio Farma, Indonesia. The aim is to develop a rotavirus vaccine starting from birth that could improve the implementation, safety, and effectiveness of vaccines. METHODS: A multi-site phase I study of a human neonatal RV3 rotavirus vaccine (Bio Farma) in adults, children, neonates in Indonesia from April 2018 to March 2019. The adult and child cohorts were open-labeled single-dose, while the neonatal cohort was randomized, double-blind, and placebo-controlled three-doses at the age of 0-5 days, 8-10 weeks, and 12-14 weeks. The primary objective was to assess the safety of vaccines with the immunogenicity and vaccine virus fecal shedding as the secondary endpoints in neonates. RESULTS: Twenty-five adults, 25 children, and 50 neonates were recruited, and all but one in the neonatal cohort completed all study procedures. Three serious adverse events were reported (1 adult & 2 neonates), but none were assessed related to investigational product (IP). The neonatal vaccine group had a significantly higher positive immune response (cumulative seroconverted SNA and IgA) 28 days after three doses than those in the placebo group (72% vs. 16.7%, respectively). The GMT of serum IgA in the vaccine group was significantly higher at post IP dose 1 (p

In the present study, a range of serum biomarkers were quantified in suspected cases of adverse events following YF immunization (YEL-AEFI) to propose a reliable laboratorial algorithm to discriminate confirmed YEL-AEFI (“A1” class) from cases with other illnesses (“C” class). Our findings demonstrated that increased levels of CXCL8, CCL2, CXCL10, IL-1β, IL-6 and TNF-α were observed in YEL-AEFI (“A1” and “C” classes) as compared to primary vaccines without YEL-AEFI [PV(day 3–28)] and reference range (RR) controls. Notably, increased levels of CCL3, CCL4, CCL2, CCL5, IL-1β, IL-15, IL-1Ra and G-CSF were found in “A1” as compared to “C” class. Venn diagrams analysis allowed the pre-selection of biomarkers for further analysis of performance indices. Data demonstrated that CCL3, CCL5, IL-15 and IL-1Ra presented high global accuracy (AUC = 1.00) to discriminate “A1” from “C”. Decision tree was proposed with a reliable algorithm to discriminate YEL-AEFI cases according to cause-specific definitions with outstanding overall accuracy (91%). CCL3, CCL5, IL-15 and IL-1Ra appears as root attributes to identify “A1” followed by VEGF as branch nodes to discriminate Wild Type YFV infection (“C(WT-YFV)”) from cases with other illnesses (“C*”). Together, these results demonstrated the applicability of serum biomarker measurements as putative parameters towards the establishment of accurate laboratorial tools for complementary differential diagnosis of YEL-AEFI cases.

Introduction Annually more than 100,000 Japanese encephalitis (JE) cases and 25,000 deaths worldwide are caused by JE virus infection. More than 15 JE vaccines are currently in use worldwide. It is unknown whether any of the vaccines is superior to the others in terms of immunogenicity and safety. Methods Four databases were systematically searched for randomised controlled trials that compared two or more types of JE vaccines. Vaccines were classified into four classes: inactivated mouse brain-derived (oldest class), inactivated Vero cell, live chimeric, and live attenuated. Network meta-analysis was used to generate mixed effect estimates against inactivated mouse brain-derived vaccines for seroconversion, and against placebo for adverse event (AE) and severe adverse event (SAE). Results 23 studies (38,496 participants) were included. All newer vaccine classes had better immunogenicity, the difference was statistically significant for inactivated Vero cell (OR = 2.98; 95 %CI: 1.02–8.65) and live chimeric (OR = 5.93; 95 %CI: 1.73–20.32) vaccines. Inactivated mouse-derived vaccines had the highest odds for AEs (OR = 2.27; 95 %CI: 1.59–3.23), the odds of AE of newer vaccines was not different to placebo. There was no difference in SAEs across vaccine classes. Conclusions All newer JE vaccines have comparable safety profiles, live chimeric and inactivated Vero cell vaccines are the most immunogenic among the newer vaccine classes.

The World Health Organization (WHO) recommends the use of oral cholera vaccines (OCVs) as part of an integrated control program, both in highly endemic settings and during cholera epidemics. The available and internationally recommended WHO-prequalified OCVs (Dukoral, Shanchol, Euvichol) contain multiple heat and formalin-killed V. cholerae strains of Inaba and Ogawa serotypes. MSD Wellcome Trust Hilleman Laboratories Pvt. Ltd. in technical collaboration with University of Gothenburg, Sweden has developed a new single strain OCV, Hillchol. This vaccine consists of formaldehyde-inactivated whole cell El Tor V. cholerae O1 bacteria engineered into the Hikojima serotype for stable expression of both the Ogawa (AB) and Inaba (AC) LPS antigens on the bacterial surface. We evaluated the safety and immunogenicity of this novel and potentially much less expensive OCV in comparison with Shanchol.We conducted a randomized, non-inferiority, age-descending clinical trial of OCV (Hillchol vs. Shanchol) in the Mirpur area of Dhaka city from July 2016 to May 2017. This study was carried out in three different age cohorts (1-5, 5-17 and ≥18 years old). Two doses of vaccine were given at 14 days intervals to 560 healthy participants.No serious adverse events were reported. There were no significant differences in the rates of adverse events between the test vaccine (Hillchol) and the comparator (Shanchol) group. Serum vibriocidal antibody responses in all age groups combined were comparable for all the O1 Ogawa (59% vs. 67%; 90% CI of difference: -14.55, -0.84) and Inaba (70% vs. 71%; 90% CI of difference: -7.24, 5.77) serotypes, showing that the Hillchol vaccine was non-inferior to Shanchol. This new vaccine was also non-inferior to Shanchol in the different age strata.The safety and immunogenicity profile of the new OCV Hillchol is comparable to Shanchol in persons residing in a cholera-endemic setting. ClinicalTrials.gov number: NCT02823899.

Background Understanding the safety of vaccines is critical to inform decisions about vaccination. Our objective was to conduct a systematic review of the safety of vaccines recommended for children, adults, and pregnant women in the United States. Methods We searched the literature in November 2020 to update a 2014 Agency for Healthcare Research and Quality review by integrating newly available data. Studies of vaccines that used a comparator and reported the presence or absence of key adverse events were eligible. Adhering to Evidence-based Practice Center methodology, we assessed the strength of evidence (SoE) for all evidence statements. The systematic review is registered in PROSPERO (CRD42020180089). Results Of 56,603 reviewed citations, 338 studies reported in 518 publications met inclusion criteria. For children, SoE was high for no increased risk of autism following measles, mumps, and rubella (MMR) vaccine. SoE was high for increased risk of febrile seizures with MMR. There was no evidence of increased risk of intussusception with rotavirus vaccine at the latest follow-up (moderate SoE), nor of diabetes (high SoE). There was no evidence of increased risk or insufficient evidence for key adverse events for newer vaccines such as 9-valent human papillomavirus and meningococcal B vaccines. For adults, there was no evidence of increased risk (varied SoE) or insufficient evidence for key adverse events for the new adjuvanted inactivated influenza vaccine and recombinant adjuvanted zoster vaccine. We found no evidence of increased risk (varied SoE) for key adverse events among pregnant women following tetanus, diphtheria, and acellular pertussis vaccine, including stillbirth (moderate SoE). Conclusions Across a large body of research we found few associations of vaccines and serious key adverse events; however, rare events are challenging to study. Any adverse events should be weighed against the protective benefits that vaccines provide.

The Coronavirus Disease 2019 (COVID-19) pandemic has had a devastating impact on global health, and has resulted in an unprecedented, international collaborative effort to develop vaccines to control the outbreak, protect human lives, and avoid further social and economic disruption. Mass vaccination campaigns are underway in multiple countries and are expected worldwide once more vaccine becomes available. Some early candidate vaccines use novel platforms, such as mRNA encapsulated in lipid nanoparticles, and relatively new platforms, such as replication-deficient viral vectors. While these new vaccine platforms hold promise, limited safety data in humans are available. Serious health outcomes linked to vaccinations are rare, and some outcomes may occur incidentally in the vaccinated population. Knowledge of background incidence rates of these medical conditions is a critical component of vaccine safety monitoring to aid in the assessment of adverse events temporally associated with vaccination and to put these events into context with what would be expected due to chance alone. A list of 22 potential adverse events of special interest (AESI), including neurologic, autoimmune, and cardiovascular disorders, was compiled by subject matter experts at the U.S. Food and Drug Administration and the Centers for Disease Control and Prevention. The most recently available U.S. background rates for these medical conditions, overall and by age, sex, and race/ethnicity (when available), were sourced from reported statistics (data published by medical panels/ associations or federal government reports), and literature reviews in PubMed. This review provides estimates of background incidence rates for medical conditions that may be monitored or studied as AESI during safety surveillance and research for COVID-19 vaccines and other new vaccines.

Quadrivalent influenza inactivated vaccine (IIV4) is more likely to provide wider protection against yearly circulating influenza viruses than trivalent inactivated influenza vaccine (IIV3). In this study, a total of 320 participants were allocated to four age cohorts (6-35 months, 3-8 years, 9-17 years, and ≥ 18 years; 80 participants/cohort) according to their actual date of birth. Participants in each cohort were randomly assigned to two groups to receive intramuscular injection of the trial vaccine or the comparative vaccine in a one-dose (3-8 years, 9-17 years,and ≥ 18 years) schedule on day 0 or two-dose (6-35 months cohort) schedule on day 0 and 28. The first objective is to evaluate the safety and immunogenicity of the full-dose subunit non-adjuvanted IIV4 (FD-subunit NAIIV4) we developed versus an active-control, China-licensed split-virion NAIIV4, in people ≥ 3 years. The second objective is to evaluate the safety and immunogenicity of FD-subunit NAIIV4 versus the half-dose (HD-subunit NAIIV4) in toddlers aged 6-35 months. Results showed that all adverse reactions noted were rare, mild, and self-limited. In ≥ 3 years cohorts, systemic adverse reactions in FD-subunit NAIIV4 groups were less than the active control split-virion NAIIV4 groups ([Systemic adverse reaction rates (95%CI)], 15.0 (8.6-21.4) versus 19.2(12.1-26.2), p = 0.391). The overall seroprotection efficacy after vaccination were comparable between FD-subunit NAIIV4 and the active control split-virion NAIIV4([Seroprotection rates (95%CI)], H1N1, 99.2(81.3-100.0) versus 94.9(90.9-98.9), p = 0.117; H3N2, 81.7(74.7-88.6) versus 82.1(75.1-89.0), p = 0.939; BV, 75.8(68.2-83.5) versus 74.4(66.4-82.3), p = 0.793; BY, 94.2(90.0-98.4) versus 92.3(87.5-97.1), p = 0.568). Additionally, FD-subunit NAIIV4 has comparable safety and better seroprotection versus that of the half-dose in 6-35 months toddlers groups ([Total adverse reaction rates (95%CI)], 37.5(18.5-56.5) versus 47.5(26.1-68.9), p = 0.366) ([Seroprotection rates (95%CI)], H1N1, 85(56.4-100.0) versus 75.7(47.6-100.0), p = 0.117; H3N2, 50(28.1-71.9) versus 29.7(12.2-47.3), p = 0.070; BV, 75(48.2-100.0) versus 29.7(12.2-47.3), p < 0.001; BY, 75(48.2-100.0) versus 56.8(32.5-81.0), p = 0.091). As a result, the FD-subunit NAIIV4 we developed is safe and effective to provide broader and adequate protection against the circulating influenza viruses during 2018-2019, which could be an essential component of the global preventive strategy for influenza pandemic.

Background and Aims ROTAVAC® (frozen formulation stored at −20 °C) and ROTAVAC 5D® (liquid formulation stable at 2–8 °C) are rotavirus vaccines derived from the 116E human neonatal rotavirus strain, developed and licensed in India. This study evaluated and compared the safety and immunogenicity of these vaccines in an infant population in Zambia. Methods We conducted a phase 2b, open-label, randomized, controlled trial wherein 450 infants 6 to 8 weeks of age were randomized equally to receive three doses of ROTAVAC or ROTAVAC 5D, or two doses of ROTARIX®. Study vaccines were administered concomitantly with routine immunizations. Blood samples were collected pre-vaccination and 28 days after the last dose. Serum anti-rotavirus IgA antibodies were measured by ELISA, with WC3 and 89–12 rotavirus strains as viral lysates in the assays. The primary analysis was to assess non-inferiority of ROTAVAC 5D to ROTAVAC in terms of the geometric mean concentration (GMC) of serum IgA (WC3) antibodies. Seroresponse and seropositivity were also determined. Safety was evaluated as occurrence of immediate, solicited, unsolicited, and serious adverse events after each dose. Results The study evaluated 388 infants in the per-protocol population. All three vaccines were well tolerated and immunogenic. The post-vaccination GMCs were 14.0 U/mL (95% CI: 10.4, 18.8) and 18.1 U/mL (95% CI: 13.7, 24.0) for the ROTAVAC and ROTAVAC 5D groups, respectively, yielding a ratio of 1.3 (95% CI: 0.9, 1.9), thus meeting the pre-set non-inferiority criteria. Solicited and unsolicited adverse events were similar across all study arms. No death or intussusception case was reported during study period. Conclusions Among Zambian infants, both ROTAVAC and ROTAVAC 5D were well tolerated and the immunogenicity of ROTAVAC 5D was non-inferior to that of ROTAVAC. These results are consistent with those observed in licensure trials in India and support use of these vaccines across wider geographical areas.

Public health officials warn that the greatest barrier to widespread vaccination against Covid-19 will not be scientific or technical, but the considerable public hesitancy to take a novel vaccine. Understanding the factors that influence vaccine acceptance is critical to informing public health campaigns to combat public fears and ensure broad uptake when a vaccine becomes available. Employing a conjoint experiment embedded on an online survey of almost 2,000 adult Americans, we show that the effects of seven vaccine attributes on subjects’ willingness to vaccinate vary significantly across subgroups. For example, vaccine efficacy was significantly more influential on vaccine acceptance among whites than among Blacks, while bringing a vaccine to market under a Food and Drug Administration Emergency Use Authorization had a stronger adverse effect on willingness to vaccinate among older Americans and women. Democrats were more sensitive to vaccine efficacy than Republicans, and both groups responded differently to various endorsements of the vaccine. We also explore whether past flu vaccination history, attitudes toward general vaccine safety, and personal contact with severe cases of Covid-19 can explain variation in group vaccination hesitancy. Many subgroups that exhibit the greatest Covid-19 vaccine hesitancy do not report significantly lower frequencies of flu vaccination. Several groups that exhibit greater Covid-19 vaccine hesitancy also report greater concerns about vaccine safety generally, but others do not. Finally, subgroup variation in reported personal contact with severe cases of Covid-19 does not strongly match subgroup variation in vaccine acceptance.

A major challenge for HIV vaccine development is to raise anti-envelope antibodies capable of recognizing and neutralizing diverse strains of HIV-1. Accordingly, a full length single chain (FLSC) of gp120-CD4 chimeric vaccine construct was designed to present a highly conserved CD4-induced (CD4i) HIV-1 envelope structure that elicits cross-reactive anti-envelope humoral responses and protective immunity in animal models of HIV infection. IHV01 is the FLSC formulated in aluminum phosphate adjuvant. We enrolled 65 healthy adult volunteers in this first-in-human phase 1a randomized, double-blind, placebo-controlled study with three dose-escalating cohorts (75 µg, 150 µg, and 300 µg doses). Intramuscular injections were given on weeks 0, 4, 8, and 24. Participants were followed for an additional 24 weeks after the last immunization. The overall incidence of adverse events (AEs) was not significantly different between vaccinees and controls. The majority (89%) of vaccine-related AE were mild. The most common vaccine-related adverse event was injection site pain. There were no vaccine-related serious AE, discontinuation due to AE, intercurrent HIV infection, or significant decreases in CD4 count. By the final vaccination, all vaccine recipients developed antibodies against IHV01 and demonstrated anti-CD4i epitope antibodies. The elicited antibodies reacted with CD4 non-liganded Env antigens from diverse HIV-1 strains. Antibody-dependent cell-mediated cytotoxicity against heterologous infected cells or gp120 bound to CD4+ cells was evident in all cohorts as were anti-gp120 T-cell responses. IHV01 vaccine was safe, well tolerated, and immunogenic at all doses tested. The vaccine raised broadly reactive humoral responses against conserved CD4i epitopes on gp120 that mediates antiviral functions.

Background Seasonal Influenza is still considered associated with seasonal morbidity and hospitalization in the elderly population. The World Health Organization (WHO) recommended seasonal quadrivalent influenza vaccine (QIV) to reduce burden of two currently circulating influenza B lineages. Until 2019 Korean National Immunization Program (NIP) recommended trivalent influenza vaccine (TIV) after ongoing debates on cost effectiveness of QIV for elderly population. Although influenza vaccine only showed modest effect on reducing influenza in elderly, this study aimed to evaluate the immunogenicity and safety of inactivated QIV in healthy participants ≥ 65 years of age. Methods A total of 274 healthy participants aged ≥ 65 years received a QIV. Seroconversion-based vaccine efficacy of 4 strains of seasonal influenza was assessed 21 days after vaccination and adverse events were monitored until 180 days after vaccination. Results The percentages of participants seroconverted after vaccination on HI antibody against each strain were 36.5% (99/271) to A/H1N1, 47.6% (129/271) to A/H3N2, 40.6% (110/271) to B Yamagata, and 49.1% (133/271) to B Victoria. The percentages of participants seroprotected after vaccination on HI antibody against each strain were 81.2% (220/271) to A/H1N1, 98.5% (267/271) to A/H3N2, 95.2% (258/271) to B Yamagata, and 93.7% (254/271) to B Victoria. There was no serious adverse event (SAE) related with the study vaccine. Conclusion The quadrivalent split influenza vaccine is expected to offer seroprotection against influenza A and both influenza B lineages even in the elderly population.

This is a Brighton Collaboration Case Definition of the term "Acute Respiratory Distress Syndrome - ARDS" to be utilized in the evaluation of adverse events following immunization. The Case Definition was developed by a group of experts convened by the Coalition for Epidemic Preparedness Innovations (CEPI) in the context of active development of vaccines for SARS-CoV-2 vaccines and other emerging pathogens. The case definition format of the Brighton Collaboration was followed to develop a consensus definition and defined levels of certainty, after an exhaustive review of the literature and expert consultation. The document underwent peer review by the Brighton Collaboration Network and by selected Expert Reviewers prior to submission. The comments of the reviewers were taken into consideration and edits incorporated in this final manuscript.

Background We assessed the 10-year efficacy, immunogenicity and safety of two doses of a combined measles-mumps-rubella-varicella vaccine (MMRV) or one dose of a monovalent varicella vaccine (V) in children from Czech Republic, Lithuania, Poland, Romania and Slovakia. Methods This was a phase IIIB follow-up of an observer-blind, randomized, controlled trial (NCT00226499). In phase A, healthy children aged 12–22 months from 10 European countries were randomized in a 3:3:1 ratio to receive two doses of MMRV (MMRV group), one dose of MMR followed by one dose of V (MMR + V group), or two doses of MMR (MMR; control group), 42 days apart. Vaccine efficacy (VE) against varicella (confirmed by viral DNA detection or epidemiological link and clinical assessment) was calculated with 95% confidence intervals using Cox proportional hazards regression model. Immunogenicity was assessed as seropositivity rates and geometric mean concentrations (GMCs). Solicited and unsolicited adverse events (AEs) and serious AEs (SAEs) were recorded. Results A total of 3705 children were vaccinated (1590, MMRV group; 1586, MMR + V group; 529, MMR group). There were 663 confirmed varicella cases (47, MMRV group; 349, MMR + V group; 267, MMR group). VE ranged between 95.4% (Lithuania) and 97.4% (Slovakia) in the MMRV group and between 59.3% (Lithuania) and 74% (Slovakia) in the MMR + V group. At year 10, seropositivity rates were 99.5%–100% in the MMRV group, 98%–100% in the MMR + V group and 50%–100% in the MMR control group, and the anti-VZV antibody GMCs were comparable between MMRV and MMR + V groups. The occurrence of solicited and unsolicited AEs was similar across groups and no SAE was considered as vaccination-related. No new safety concerns were identified. Conclusions Our results indicated that two doses of varicella zoster virus-containing vaccine provided better protection than one dose against varicella and induced antibody responses that persisted 10 years post-vaccination.

Background: Efficacy of the nine-valent human papillomavirus (9vHPV; HPV types 6/11/16/18/31/33/45/52/58) vaccine was demonstrated in a phase 3 study in women 16 & ndash;26 years of age. We present a phase 3 immunogenicity and safety study of the 9vHPV vaccine in women 27 & ndash;45 versus 16 & ndash;26 years of age. Methods: This international, open-label study (NCT03158220) was conducted in women 16 & ndash;45 years of age. Participants (16 & ndash;26 years, n = 570 and 27 & ndash;45 years, n = 642) received a three-dose 9vHPV vaccination regimen (day 1, month 2, month 6). Month 7 geometric mean titers (GMTs) and seroconversion percentages to anti-HPV 6/11/16/18/31/33/45/52/58 were assessed. Participants were followed for safety throughout the study. Results: At month 7, anti-HPV 6/11/16/18/31/33/45/52/58 GMTs in women 27 & ndash;45 years were compared to those in women 16 & ndash;26 years of age. The primary hypothesis of non-inferiority of anti-HPV 16/18/31/33/45/52/58 GMTs in older versus younger women was met. The lower bound of the GMT ratio 95% confidence interval (27 & ndash;45 years to 16 & ndash;26 years) was 0.60 & ndash;0.67 depending on HPV type, exceeding the non-inferiority margin of 0.5 for all HPV types. Month 7 seroconversion percentages in women 27 & ndash; 45 years of age were >99% for all HPV types. Injection-site and vaccine-related systemic adverse events (AEs) were observed in 87.5% and 25.1% of women 16 & ndash;26 years, and 85.2% and 24.1% of women 27 & ndash; 45 years of age, respectively; no vaccine-related serious AEs were reported and no deaths occurred during the study. Conclusions: The 9vHPV vaccine elicited non-inferior anti-HPV GMTs in women 27 & ndash;45 years compared with women 16 & ndash;26 years of age for HPV 16/18/31/33/45/52/58. The vaccine was generally well tolerated with a similar AE profile across the age groups. These data support bridging 9vHPV vaccine efficacy findings in women 16 & ndash;26 years to women 27 & ndash;45 years of age. Clinical trial registration NCT03158220. (c) 2021 Elsevier Ltd. All rights reserved.

The inactivated trivalent influenza vaccine (TIV) offers limited protection when two influenza B lineages co-circulate or when there is a vaccine mismatch (i.e., discordance in the predominant circulating B strain and WHO-recommended B strain). Inactivated quadrivalent influenza vaccine (QIV) may reduce the burden of influenza. Here, we report the results of a phase 3 clinical trial that evaluated the immunogenicity and safety of a novel QIV, GC3110A, in Korean children aged 6–35 months, which has been approved and is currently in use in Korea. The study involved two parts. In Part 1, the safety of GC3110A was evaluated in 10 subjects. After none of the subjects reported grade 3 adverse events (AEs), we proceeded to Part 2. Part 2 was a randomized, double-blind, multicenter phase 3 trial wherein we compared the immunogenicity and safety of GC3110A with those of a licensed control TIV. Immunogenicity was evaluated by measuring hemagglutination inhibition titers. The 200 participants enrolled in Part 2 were randomized in a 4:1 ratio to receive GC3110A or control TIV. The study vaccine group met both primary (i.e., the lower limit of 95% confidence interval [CI] of the seroconversion rate exceeds 40% for four strains) and secondary (i.e., the lower limit of 95% CI of the seroprotection rate exceeds 70% for four strains) immunogenicity endpoints. There was no significant between-group difference in the seroconversion rate, seroprotection rate, and geometric mean titer for the shared strains. However, the study vaccine group demonstrated significantly higher immunity for the additional strain B/Yamagata. In the safety analysis, there was no significant between-group difference in the proportion of participants with solicited local AEs, solicited systemic AEs, and unsolicited AEs. In conclusion, the results indicate that GC3110A has comparable immunogenicity and safety to those of TIV. Clinical Trial Registry Number: NCT03285997.

Introduction Two types of enterovirus 71 (EV71) vaccines, manufactured using human diploid (H2) and Vero cells, have been administered in Jiangsu Province, China since 2017. In this study, we evaluated their safety profiles using records collected from the Chinese National Adverse Events Following Immunization (AEFIs) Information System (CNAEFIS) and Electronic Immunization Registries System (EIRS) between 2017 and 2019. Methods Demographic characteristics of the patients, AEFI incidence rates(IRs), symptoms, and time intervals were summarized from the reported AEFI data in the CNAEFIS. Also, the administered doses of the two vaccines were exported from the EIRS to calculate the IRs of AEFIs and thus compare the AEFIs between the two types of EV71 vaccines. Results In total, 209, 407, and 344 AEFIs cases following EV71 vaccine administration were reported during 2017, 2018, and 2019, respectively, yielding IRs of 59.2, 48.2, and 54.2 per 100,000 doses, respectively. Fever, irritability, allergic eruptions, fatigue, loss of appetite, redness and induration at the injection site were the most commonly reported AEFIs. No significant differences in rare reactions were found between the two types of EV71 vaccinations. The majority of AEFIs were developed within 30 min to 3 days after administration. Conclusion EV71 vaccines showed satisfactory safety profiles since their first use 3 years ago in the Jiangsu Province. The AEFI profiles were identical to those in pre-marketing studies; most AEFIs after vaccination were mild and common. More active surveillance studies should be performed to provide more comprehensive post-marketing safety data.

Quadrivalent high-dose inactivated influenza vaccine (Fluzone® High-Dose Quadrivalent, IIV4-HD) was licensed in the USA in 2019 for adults ≥ 65 years of age. This Phase II study examined safety and immunogenicity of 3 dose formulations of IIV4-HD in healthy children. In a randomized, modified double-blind, active-controlled trial in the USA and Canada, 661 children aged 6 months through < 18 years received 1 or 2 doses intramuscularly of standard-dose quadrivalent influenza vaccine (IIV4-SD; 15 µg HA/strain), IIV4-HD at 3 dose levels (30, 45, and 60 µg HA/strain), or adjuvanted trivalent influenza vaccine (aIIV3, 7.5 µg HA/strain). Rates of unsolicited AEs were similar irrespective of dose. No treatment-related serious adverse events or deaths were reported. Reactogenicity was slightly higher for IIV4-HD than IIV4-SD, although most solicited reactions were grade 1 or 2. Hemagglutination inhibition (HAI) and seroneutralization antibody titers were measured 28-35 days after each dose. Geometric mean HAI titers increased with increasing hemagglutinin dose, especially in children 6 months through < 3 years. For IIV4-HD 60 µg, in participants 6 months through < 18 years of age, the geometric mean titer ratio (95% confidence interval) versus IIV4-SD was 1.35 (0.94, 1.94) for A/H1N1, 2.51 (1.77, 3.55) for A/H3N2, 1.60 (1.17, 2.18) for B/Victoria, and 1.51 (1.13, 2.03) for B/Yamagata. The GMT ratio (95% confidence interval) for IIV4-HD 60 µg versus IIV4-SD was highest for participants 6 months through < 3 years of age: 4.24 (2.05, 8.76) for A/H1N1, 3.14 (1.53, 6.44) for A/H3N2, 2.04 (1.10, 3.77) for B/Victoria, and 1.92 (1.08, 3.41) for B/Yamagata; similarly, seroneutralization antibody GMT ratio was highest in these participants: 170 (84.6, 340) for A/H1N1, 7.13 (4.90, 10.4) for A/H3N2, 35.8 (22.1, 58.1) for B/Victoria, and 22.7 (14.7, 35.0) for B/Yamagata. This study showed that IIV4-HD (60 µg HA/strain) provides improved immunogenicity without affecting vaccine safety in children.

Background This first in human study was designed as an open label clinical trial to assess the safety and tolerability of Serum Institute of India Pvt. Ltd. (SIIPL) Tdap vaccine in healthy adult volunteers, aged 18–45 years. Methods A total of 24 healthy adults were administered a 0.5 ml single dose of SIIPL Tdap vaccine intramuscularly, and were followed for one month for safety outcomes viz., immediate, solicited, unsolicited and serious adverse events. Results 23 subjects completed the study in compliance with the study protocol. None of the participants experienced any immediate adverse events or any local or systemic solicited adverse events. Conclusion Tdap vaccine manufactured by Serum Institute of India Pvt. Ltd. is safe and well tolerable in adults. It was concluded that further clinical development of this vaccine should continue to assess its safety and immunogenicity, in the target population. Clinical Trial Registration – CTRI/2017/03/008003.

Introduction In a first-in-human study immune responses to rabies virus glycoprotein (RABV-G)-mRNA vaccine were dependent on the route of administration, necessitating specialized devices. Following successful preclinical studies with mRNA encapsulated in lipid nanoparticles (LNP), we tested an mRNA-LNP formulation (CV7202). Methods In this phase 1, multi-center, controlled study in Belgium and Germany we enrolled 55 healthy 18–40-year-olds to receive intramuscular injections of 5 μg (n = 10), 1 μg (n = 16), or 2 μg (n = 16) CV7202 on Day 1; subsets (n = 8) of 1 μg and 2 μg groups received second doses on Day 29. Controls (n = 10) received rabies vaccine, Rabipur, on Days 1, 8 and 29. Safety and reactogenicity were assessed up to 28 days post-vaccination using diary cards; immunogenicity was measured as RABV-G-specific neutralizing titers (VNT) by RFFIT and IgG by ELISA. Results As i nitially tested doses of 5 μg CV7202 elicited unacceptably high reactogenicity we subsequently tested 1 and 2 μg doses which were better tolerated. No vaccine-related serious adverse events or withdrawals occurred. Low, dose-dependent VNT responses were detectable from Day 15 and by Day 29%, 31% and 22% of 1, 2 and 5 μg groups, respectively, had VNTs ≥ 0·5 IU/mL, considered an adequate response by the WHO. After two 1 or 2 μg doses all recipients had titers ≥ 0.5 IU/mL by Day 43. Day 57 GMTs were not significantly lower than those with Rabipur, which elicited adequate responses in all vaccinees after two doses. CV7202-elicited VNT were significantly correlated with RABV-G-specific IgG antibodies (r2 = 0.8319, p Conclusions Two 1 μg or 2 μg doses of CV7202 were well tolerated and elicited rabies neutralizing antibody responses that met WHO criteria in all recipients, but 5 μg had unacceptable reactogenicity for a prophylactic vaccine. ClinicalTrials.gov Identifier: NCT03713086.

Introduction Passive surveillance is recommended globally for the detection of adverse events following immunisation (AEFI) but this has significant challenges. Use of Mobile health for vaccine safety surveillance enables a consumer-centred approach to reporting. The Stimulated Telephone Assisted Rapid Safety Surveillance (STARSS) a randomised control trial (RCT) sought to evaluate the efficacy and acceptability of SMS for AEFI surveillance. Methods Multi-centre RCT, participants were adult vaccinees or parents of children receiving any vaccine at a trial site. At enrolment randomisation occurred to one of two SMS groups or a control group. Prompts on days 2, 7 and 14 post-immunisation, were sent to the SMS group, to ascertain if a medical event following immunisation (MEFI) had occurred. No SMS's were sent to the control participants. Those in the SMS who notified an MEFI were pre-randomised to complete a computer assisted telephone interview or a web based report to determine if an AEFI had occurred whilst an AEFI in the controls was determined by a search for passive reports. The primary outcome was the AEFI detection rate in the SMS group compared to controls. Results We enrolled 6,338 participants, who were equally distributed across groups and who received 11,675 vaccines. The SMS group (4,225) received 12,675 surveillance prompts with 9.8% being non-compliant and not responding. In those that responded 90% indicated that no MEFI had been experienced and 184 had a verified AEFI. 6 control subjects had a reported AEFI. The AEFI detection rate was 13 fold greater in the SMS group when compared with controls (4.3 vs 0.3%). Conclusion We have demonstrated that the STARSS methodology improves AEFI detection. Our findings should inform the wider use of SMS-based surveillance which is particularly relevant since establishing robust and novel pharmacovigilance systems is critical to monitoring novel vaccines which includes potential COVID vaccines.

Background The quadrivalent human papillomavirus (qHPV; HPV6/11/16/18) vaccine was approved for use in Chinese women aged 20–45 years in 2017. This Phase 3, open-label study (NCT03493542) aimed to assess immunogenicity and safety of the qHPV vaccine in Chinese girls aged 9–19 years versus Chinese young women aged 20–26 years; we report results from Day 1 through Month 7. The study will continue through Month 60 to assess antibody persistence in Chinese girls aged 9–19 years. Methods Participants aged 9–26 years received three doses of the qHPV vaccine (Day 1, Month 2, Month 6). Geometric mean titers (GMTs) and seroconversion percentages for anti-HPV6/11/16/18 antibodies were determined by competitive Luminex immunoassay (cLIA) in serum samples obtained on Day 1 and at Month 7. Injection-site adverse events (AEs) and systemic AEs within 30 days post-vaccination, and serious AEs (SAEs) occurring at any time during the study, were recorded. Results In total, 766 participants (383 aged 9–19 years; 383 aged 20–26 years) were enrolled and received ≥1 vaccine dose. All participants in the per-protocol immunogenicity population of both age groups seroconverted to each of the vaccine HPV types at Month 7. Anti-HPV6/11/16/18 antibody GMTs at Month 7 in participants aged 9–19 years were non-inferior to those in participants aged 20–26 years. Injection-site AEs and systemic AEs were reported by 36.6% and 49.3% of 9–19-year-olds, and 40.7% and 54.8% of 20–26-year-olds, respectively. There were no vaccine-related SAEs. No participants discontinued the vaccine due to an AE and no deaths were reported. Conclusion Antibody responses induced by the 3-dose qHPV vaccination regimen in Chinese girls aged 9–19 years were non-inferior to those in Chinese young women aged 20–26 years. The vaccine was generally well tolerated in the study population. ClinicalTrials.gov Identifier: NCT03493542.

[EN] Trial Design: An interventional, phase 4, single group assignment, without masking (open label), preventive clinical trial was carried out in health workers with biological risk in their tasks, who have been filed as non-responders to conventional vaccination against Hepatitis B. Methods: 67 health workers with biological risk in their tasks, who have been filed as non-responders to conventional vaccination against Hepatitis B, were enrolled in the Clinical Trial. All participants were from 18 years up to 64 years old. Inclusion Criteria: NHS workers -including university students doing their internships in health centres dependent on the National Health System (inclusion of students is regulated and limited by specific instructions on labour prevention in each autonomous community)- classified as non-responders. The criteria defining them as non-responders to the conventional hepatitis B vaccine is anti HBsAb titers < 10 mUI/ml following the application of six doses of conventional vaccine at 20 lg doses (two complete guidelines). The objective of this study was to provide Health workersstaff with an additional protection tool against hepatitis B infection, and to evaluate the efficacy of the adjuvanted vaccine in healthy non-responders to conventional hepatitis B vaccine. The primary outcome was the measurement of antibody antiHBs before the first Fendrix dose and a month after the administration of each dose. Other outcome was collection of adverse effects during administration and all those that could be related to the vaccine and that occur within 30 days after each dose. In this study, only one group was assigned. There was no randomization or masking. Results: The participants were recruited between April 13, 2018 and October 31, 2019. 67 participants were enrolled in the Clinical Trial and included the analyses. The primary immunisation consists of 4 separate 0.5 ml doses of Fendrix , administered at the following schedule: 1 month, 2 months and 6 months from the date of the first dose. Once the positivity was reached in any of the doses, the participant finished the study and was not given the following doses. 68.66% (46 out 67) had a positive response to first dose of Fendrix. 57.14% (12 out 21) had a positive response to second dose of Fendrix . 22.22% (2 out 9) had a positive response to third dose of Fendrix and 42.96% (3 out 7) had a positive response to last dose of Fendrix. Overall, 94.02% (64 out 67) of participants had a positive response to Fendrix . No serious adverse event occurred. Conclusions: The use of Fendrix , is a viable vaccine alternative for NHS workers classified as ‘‘nonresponders”. Revaccination of healthy non-responders with Fendrix, resulted in very high proportions of responders without adverse events. Trial registration: The trial was registered in the Spanish National Trial Register (REEC), ClinicalTrials.gov and inclusion has been stopped (identifier NCT03410953; EudraCT-number 2016-004991-23). Funding: GRS 1360/A/16: Call for aid for the financing of research projects in biomedicine, health management and socio-health care to be developed in the centres of the Regional Health Management of Autonomous Community of Castile-Leon. In addition, this work has been supported by the Spanish Platform for Clinical Research and Clinical Trials, SCReN (Spanish Clinical Research Network), funded by the Subdirectorate General for Research Evaluation and Promotion of the Carlos III Health Institute (ISCIII), through the project PT13/0002/0039 and project PT17/0017/0023 integrated in the State Plan for R&D&I 2013–2016 and co-financed by and the European Regional Development Fund (ERDF).

Introduction In 2006 and 2008, two live, oral rotavirus vaccines, RotaTeq (RV5) and Rotarix (RV1), were introduced into the routine immunization program in the United States. A previous rotavirus vaccine, RotaShield, was associated with an increased risk of intussusception, with data suggesting an age-dependent variation in risk. Advisory Committee on Immunization Practices (ACIP) currently recommends that RV5 or RV1 immunization be initiated by age 14 weeks and 6 days and completed by 8 months 0 days. Methods We searched for U.S. VAERS reports of RV5, RV1, or unknown rotavirus vaccine brand among individuals aged ≥8 months. We analyzed reports by 2 age groups (individuals aged ≥8 months–≤5 years and ≥6 years), vaccine brand name, adverse event (AE) reported, classification of seriousness (death, non-death serious, and non-serious) and mode of exposure (direct vs. indirect exposure). For serious reports we reviewed available medical records and assigned a primary diagnosis. Results VAERS received a total of 344 U.S. reports following rotavirus vaccination among individuals ≥8 months of age, 32 (9.3%) were serious. In the younger age-group, 307 (99%) of 309 reports followed direct vaccination of the child. In contrast, in individuals aged ≥6 years, 21 (60%) of 35 reports were via potential indirect exposure to a vaccinated child. The frequently reported AEs in the younger age-group were inappropriate schedule of drug administration 104 (34%) and drug administered to patient of inappropriate age 45 (15%); in the older group these were accidental exposure 9 (26%) and eye irritation 7 (20%). No difference in the safety profile was observed between RV1 and RV5. Conclusions We did not identify any unexpected AEs for RV vaccines among individuals aged ≥8 months. Health care providers should adhere to the ACIP recommended schedule and older individuals should apply necessary precautions to prevent potential secondary exposure from vaccinated children.

Introduction Monitoring for adverse events following immunisation (AEFI) is critical for vaccine pharmacovigilance. Given the global and expanding availability of mobile phones their utility for consumer-based vaccine safety surveillance is of interest but little is known about consumer acceptability. This study nested within the Stimulated Telephone Assisted Rapid Safety Surveillance (STARSS) randomised control trial sought to evaluate the acceptability of SMS for AEFI surveillance. Methods The primary STARSS study was a multi-centre RCT evaluating the efficacy of repeated SMS prompts for AEFI surveillance with participants being adult vaccinees or parents of children receiving any vaccine. This nested study enrolled primary RCT participants who completed a detailed computer assisted telephone interview to determine their attitudes towards SMS-based surveillance and ascertain their knowledge and attitudes toward vaccine safety, efficacy, data privacy and use of electronic health records. Attitudes to surveillance and related behaviour were used as measures of acceptability. Results 20% (1200/6555) of the participants were enrolled and 1139 completed the full-length questionnaire. 96% indicated that SMS-based surveillance after immunisation to check the safety of the vaccine “should be done” but 62% of all respondents said it should be done but consent should be sought first. Neither vaccine safety attitudes nor attitudes toward privacy were associated with opposition to SMS-based surveillance. In terms of SMS related behaviour demographic rather than attitudinal factors were associated with non-compliance. Conclusion Overall, the attitude towards SMS-based surveillance was very favourable. Experiencing the SMS surveillance has the effect of reducing opposition to an SMS surveillance system, and at the same time increasing the likelihood of a preference for prior consent. Detection of a vaccine safety signal could be impeded in particular demographic groups who are non-compliant and we should undertake further research to understand why these groups are non-compliant and how this can be improved.

Background Hemorrhagic fever with renal syndrome is a serious health problem in Eurasian countries. This study aimed to evaluate the immunogenicity and safety of formalin-inactivated Hantaan virus vaccine (Hantavax®) with a 3 + 1 vaccination schedule. Methods A phase III, multi-center clinical trial was conducted to evaluate the immunogenicity and safety of Hantavax® (three primary doses and a booster dose schedule at 0, 1, 2 and 13 months) among healthy adults. Immune responses were assessed using the plaque reduction neutralizing antibody test (PRNT) and immunofluorescent antibody assay (IFA). Systemic and local adverse events were assessed. Results A total of 320 healthy subjects aged ≥19 years were enrolled. Following three primary doses of Hantavax®, the seroconversion rate was 80.97% and 92.81% by PRNT and IFA, respectively. With booster administration, seropositive rates were 67.47% and 95.68% at one-month post-vaccination according to PRNT and IFA, respectively. Solicited local and systemic adverse events were reported in 30.50–42.81% and 16.67–33.75% during the three primary dose vaccination, while those were reported 36.57% and 21.36% after the booster doses. Both local and systemic adverse events did not increase with repeated vaccinations. Conclusion Hantavax® showed a high seroconversion rate after the three-dose priming, and additional dose administration with 11-month interval induced good booster effects. (ClinicalTrials.gov Identifier: NCT02553837).

Background Japanese encephalitis (JE) virus is an important cause of neurological disease in Asia. JE vaccine is recommended for travelers with higher JE risk itineraries. Inactivated Vero cell culture-derived JE vaccine (JE-VC) is the only JE vaccine currently available in the United States. An inactivated mouse brain-derived JE vaccine (JE-MB) previously was available but production was discontinued. One JE-VC dose administered to adults previously vaccinated with ≥3 doses of JE-MB provides good short-term protection for at least one month, but data on longer-term protection are limited. We evaluated non-inferiority of the JE virus neutralizing antibody response at 12–23 months in JE-MB-vaccinated adults administered one JE-VC dose compared with JE vaccine-naive adults administered a JE-VC two-dose primary series. Methods We obtained archived sera from U.S. military personnel and performed a 50% plaque reduction neutralization test for anti-JE virus neutralizing antibodies. We compared the geometric mean titer (GMT) and seroprotection rate at 12–23 months after one JE-VC dose in previously JE-MB-vaccinated personnel and after the second JE-VC dose in previously JE vaccine-naive personnel. Non-inferiority was concluded if the lower bound of the two-sided 95% confidence interval (CI) of the GMT ratio in previously vaccinated to vaccine-naive personnel was >1/1.5. Results The GMT in previously JE-MB-vaccinated persons was 75 (95% CI 63–90) and in previously JE vaccine-naive persons was 12 (95% CI 11–14), and seroprotection rates were 94% (235/250) and 54% (135/250), respectively. The ratio of GMTs was 6.3 (95% CI: 5.0–7.7), satisfying the criterion for non-inferiority. Conclusions One JE-VC dose in previously JE-MB-vaccinated military personnel provides good protection for at least 1–2 years. The benefits of administration of a single JE-VC dose in previously JE-MB-vaccinated adults include a shorter time to completion of re-vaccination before travel, a decrease in the risk of adverse events, and reduced costs.

Objectives To compare rates of myopericarditis, severe and serious dermatological or neurological events, and other adverse events in deploying US military personnel who received or did not receive ACAM2000® (Smallpox [Vaccinia] Vaccine, Live) vaccine and to evaluate potential risk factors for development of myopericarditis. Methods Prospective observational cohort study enrolling up to 15,000 ACAM2000 recipients (Cohort 1) and up to 5000 persons otherwise eligible for ACAM2000 vaccination but not vaccinated due to recency of vaccination or characteristics of their contacts (Cohort 2). Data and specimens were collected initially and 10 (6–17) days later. Those with clinical or laboratory evidence of possible myopericarditis were referred for further evaluation and adjudication by a blinded independent review committee. The adjusted odds ratio for myopericarditis was determined by a logistic regression model controlling for age, race, gender, and exercise regimen. Results 14,667 subjects provided initial data and specimens (Cohort 1, 10,825; Cohort 2, 3842); 12,110 (Cohort 1, 8945; Cohort 2, 3165) completed Visit 2 per-protocol. A total of 125 (Cohort 1, 111; Cohort 2, 14) were referred for myopericarditis adjudication, yielding 54 (Cohort 1, 44, Cohort 2, 10) subclinical myopericarditis, 5 suspected myocarditis, 1 confirmed myocarditis, and 1 suspected pericarditis. Unadjusted myopericarditis rates were: Cohort 1, 5.7/1000 (95% CI, 4.3–7.5); Cohort 2, 3.2/1000 (95% CI, 1.7–5.8). Unadjusted and adjusted odds ratios for myopericarditis were 1.8 (95% CI: 0.9–3.6) and 1.3 (95% CI: 0.6–2.6), respectively. One hundred seventeen subjects (1.1%) in Cohort 1 and 13 (0.3%) in Cohort 2 experienced at least 1 serious adverse event. No instances of serious and severe neurological or dermatological adverse events were reported. Conclusions In this carefully screened, generally young and healthy service-member population, ACAM2000 vaccination was associated with modest non-significant increases in the risk of myopericarditis (adjusted OR, 1.3; unadjusted OR, 1.8); all but seven cases were subclinical. Clinical trials registration: ClinicalTrials.gov NCT00928577.