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The introduction of varicella vaccines into routine pediatric immunization programs has led to a considerable reduction in varicella incidence. However, there have been reports of varicella, herpes zoster, and meningitis caused by the vaccine strain of varicella-zoster virus (VZV), raising concerns. Establishing the relationship between the wild-type and vaccine strains in VZV infections among previously vaccinated individuals is crucial. Differences in the single nucleotide polymorphisms (SNPs) among vaccine strains can be utilized to identify the strain. In this study, we employed nanopore sequencing to identify VZV strains and analyzed clinical samples. We retrospectively examined vesicle and cerebrospinal fluid samples from patients with VZV infections. One sample each of the wild-type and vaccine strains, previously identified using allelic discrimination real-time PCR and direct sequencing, served as controls. Ten samples with undetermined VZV strains were included. After DNA extraction, a long PCR targeting the VZV ORF62 region was executed. Nanopore sequencing identified SNPs, allowing discrimination between the vaccine and wild-type strains. Nanopore sequencing confirmed SNPs at previously reported sites (105,705, 106,262, 107,136, and 107,252), aiding in distinguishing between wild-type and vaccine strains. Among the ten unknown samples, nine were characterized as wild strains and one as a vaccine strain. Even in samples with low VZV DNA levels, nanopore sequencing was effective in strain identification. This study validates that nanopore sequencing is a reliable method for differentiating between the wild-type and vaccine strains of VZV. Its ability to produce long-read sequences is remarkable, allowing simultaneous confirmation of known SNPs and the detection of new mutations. Nanopore sequencing can serve as a valuable tool for the swift and precise identification of wild-type and vaccine strains and has potential applications in future VZV surveillance. [ABSTRACT FROM AUTHOR]

Measles, mumps, rubella (MMR), and varicella incidence rates have increased due to the delayed vaccination schedules of children secondary to the COVID-19 pandemic. Decreased herd immunity creates a risk for immunocompetent children and immunocompromised individuals in the community. Historically, live-attenuated vaccines (MMR and varicella) were recommended before solid organ transplants. The amount of time before transplant when this is appropriate is often debated, as is the utility of vaccine titers. MMR and varicella vaccines previously were not recommended in immunocompromised patients post-solid organ transplant due to the undue risk of transmission and posed infection risk. The new literature on live-attenuated vaccines in post-transplant pediatric patients provides more insight into the vaccines' safety and efficacy. The present article aims to provide guidance on live-attenuated vaccines (MMR and varicella) in the pre-transplant and post-operative solid organ transplant phases of care in pediatric patients. [ABSTRACT FROM AUTHOR]

Background and Objective: Current regulatory labeling recommends avoiding live vaccine use in dupilumab‐treated patients. Clinical data are not available to support more specific guidance for live or live attenuated vaccines administration in dupilumab‐treated patients. Methods: Children (6 months–5 years old) with moderate‐to‐severe atopic dermatitis (AD) enrolled in a phase 2/3 clinical trial of dupilumab (LIBERTY AD PRESCHOOL Part A/B; NCT03346434) and subsequently participated in the LIBERTY AD PED‐OLE (NCT02612454). During these studies, protocol deviations occurred in nine children who received measles, mumps, rubella (MMR) vaccine with or without varicella vaccine; five with a ≤12‐week gap between dupilumab administration and vaccination and four with a >12‐week gap after discontinuing dupilumab. Results: Nine children (1 female; 8 male) had severe AD at baseline (8–56 months old). Of the nine children, five had a ≤12‐week gap ranged 1–7 weeks between dupilumab administration and vaccination who received MMR vaccine (n = 2) or MMR and varicella vaccines (n = 3); among these, one resumed dupilumab treatment as early as 2 days and four resumed treatment 18–43 days after vaccination. No treatment‐emergent adverse events, including serious adverse events and infections, were reported within the 4‐week post‐vaccination period in any children. Conclusions: In this case series of dupilumab‐treated children with severe AD who received MMR vaccine with or without varicella vaccine, no adverse effects (including vaccine‐related infection) were reported within 4 weeks after vaccination. Further studies are warranted to evaluate the safety, tolerability, and immune response to live attenuated vaccines in dupilumab‐treated patients. [ABSTRACT FROM AUTHOR]

Vaccines represent the most important medical evolution in the last two centuries allowing prevention and formally eradication of a wide number of infectious diseases. Safety and effectiveness are main issues that still require an open discussion. A few clinical reports described a critical temporal relationship between vaccination and acute nephrotic syndrome, indirectly suggesting an association. For this review, the literature was reviewed to identify articles reporting associations of nephrotic syndrome with vaccines against a vast array of infectious diseases (including bacteria, virus and Sars-Cov-2). As specific aims, we evaluated effectiveness and safety in terms of occurrence of either "de novo" nephrotic syndrome in health subjects or "relapse" in those already affected by the disease. In total, 377 articles were found; 166 duplicates and 71 non-full text, animal studies or non-English language were removed. After excluding another 50 articles not containing relevant data on generic side effects or on relapses or new onset nephrotic syndrome, 90 articles met the search criteria. Overall, studies reported the effect of vaccines in 1015 patients, plus 4 nationwide epidemiologic investigations. Limited experience on vaccination of NS patients with measles, mumps, and rubella live attenuated vaccines does not allow any definitive conclusion on their safeness. VZV has been administered more frequently without side effects. Vaccines utilizing virus inactivated, recombinant, and toxoid can be utilized without risks in NS. Vaccines for influenza reduce the risk of infections during the pandemic and are associated with reduced risk of relapse of NS typically induced by the infection. Vaccines for SARS-CoV-2 (all kinds) offer a concrete approach to reduce the pandemic. "De novo" NS or recurrence are very rare and respond to common therapies. [ABSTRACT FROM AUTHOR]

We summarize studies of varicella vaccine's effectiveness for prevention of varicella and lessons learned during the first 25 years of the varicella vaccination program in the United States. One dose of varicella vaccine provided moderate protection (82%-85%) against varicella of any severity and high protection (100%) against severe varicella, with some waning of protection over time. The 1-dose program (1995-2006) had a substantial impact on the incidence both of varicella and of severe outcomes (71%-90% decrease) although it did not prevent low-level community transmission and some outbreaks continued to occur in highly vaccinated populations. Two doses of varicella vaccine improved the vaccine's effectiveness by at least 10% against varicella of any severity, with further declines in the incidence both of varicella and of severe outcomes as well as in both number and size of outbreaks. There is no evidence for waning of the effectiveness of 2 doses of the vaccine. [ABSTRACT FROM AUTHOR]

While the varicella vaccine was created with approaches established for other live attenuated viral vaccines, novel methods to probe virus-host interactions have been used to explore the genetics, pathogenesis, and immunogenicity of the vaccine compared to wild-type varicella-zoster virus (VZV). As summarized here, a mechanism-based understanding of the safety and efficacy of the varicella vaccine has been achieved through these investigations. [ABSTRACT FROM AUTHOR]

The article presents a study which assessed how parents' confidence in childhood vaccines changed during the COVID-19 pandemic. Topics include data used in the study, trends in the percentage of parents who strongly agreed or agreed with statements presented about childhood vaccines, and the important role of pediatricians in addressing parents' concerns about childhood vaccines.

Background: Vaccine developers in China have made an increasing number of infectious diseases preventable through vaccination. An appropriate decision-making procedure is necessary for making wise decisions on whether to introduce new vaccines into the Expanded Program on Immunization (EPI). When there are several vaccines that could potentially be considered, a scientifically justifiable mechanism is needed for prioritizing and sequencing vaccines for consideration. Methods: We used a modified Delphi technique (MDT) to develop and refine an indicator system to prioritize vaccines and make policy recommendations concerning their introduction into China's EPI system. From January through May 2021, thirty-nine experts were recruited and participated in a two-round Delphi survey that was based on a set of candidate indicators obtained through a literature review and reference to the WHO vaccine introduction recommendations. Using the resulting indicator system, we conducted a third consultation with a multi-disciplinary group of experts who scored five program-eligible candidate vaccines to determine prioritization and sequencing for consideration of inclusion into the EPI. Results: Response rates of the thirty-nine experts were 100% and 97.4% across the two rounds. Authority coefficients from rounds one to three were over 0.70, reflecting the high accuracy and reliability of the consultation. Coordination coefficients of importance scores for primary, secondary, and tertiary indicators were 0.486, 0.356, 0.275 in round one, and 0.405, 0.340, and 0.236 in round two. According to the scores from 30 experts using our indicator system, the sequence and scores (1–10 scale, 10 highest) of 5 candidate vaccines were varicella (6.91), meningococcal conjugate AC (6.83), Hib (6.74), influenza (6.56), and EV71 (6.17) vaccines. Conclusions: A modified Delphi technique effectively built a scientific, rational, comprehensive, and systematic indicator system for prioritizing vaccine candidates for consideration of inclusion into the EPI. The rank order will be used by the technical working groups of China's National Immunization Advisory Committee to sequentially develop and present Evidence-to-Recommendation tables for making policy recommendations. [ABSTRACT FROM AUTHOR]

Studies have shown an increased risk of febrile convulsions (FC) after first immunization with the quadrivalent measles-mumps-rubella-varicella vaccine (MMRV) compared to a first dose of measles-mumps-rubella vaccine (MMR) only or in combination with separately administered varicella vaccine (MMR + V). Therefore, it is recommended to give MMR + V at first dose and MMRV or MMR + V at second dose. Little is known on the risk of FC after MMRV at second dose, especially whether the risk depends on age, sex, history of FC or type of first dose vaccine. A retrospective cohort study using claims data from the German Pharmacoepidemiological Research database (GePaRD) was performed in children born between January 1st, 2004 and October 31st, 2015 who received two doses of MMRV, MMR + V or MMR. Cases were defined as hospitalization with a diagnosis of FC without neurological conditions coded as main discharge diagnosis. Unadjusted and adjusted odds ratios (OR) with 95% confidence intevals (CIs) were calculated to compare the risk of FC. Stratified analyses were performed to examine potential effect modification by age, sex, history of FC or type of first dose vaccine. In the first 30 days after second dose vaccination, 464 FCs were observed in a cohort of 528,639 children with a median age of 17 months. After adjustment for potential confounders, the adjusted OR for FC in the 30 days after vaccination was 1.25 (95% CI 0.67–2.30) for MMRV compared to MMR + V and 1.04 (0.82–1.32) for MMRV compared to MMR. History of FC was the most important risk factor with an OR of 36.26 (29.30–44.89). We found no effect modification by age, sex, history of FC, or type of first dose vaccine. Use of MMRV at second dose is not associated with an increased risk of FC compared to MMR + V or MMR, irrespective of age, sex, history of FC, or type of first dose vaccine. [ABSTRACT FROM AUTHOR]

To conduct a nationwide evaluation of vaccine bidding, procurement and distribution management for understanding and improving the current situation well in mainland China. An institution survey was carried out to collect information on tendering, procurement, distribution and related issues to vaccines by structured questionnaires administered to 31 provinces in mainland China from April to July 2019. In 13 (41.9%) of 31 provinces, centralized bidding of National Immunization Program (NIP) vaccines was accomplished, and others conducted independent tendering and purchasing in 2018. For non-NIP vaccines, all provinces implemented unified bidding at the provincial level and over half (18, 58.1%) of them chose provincial public resource trading platforms, but their modes varied over provinces. Then procurement was undertaken by the district-level centers for disease control and prevention (CDC) while they were unable to choose the best option of too many vaccines targeted by the province-level CDC for local populations. The distribution modes of NIP and non-National Immunization Program (non-NIP) vaccines were similar overall in a province but very different over provinces. Main mode was that CDCs at different levels delivered about two thirds (64.5%) of NIP vaccines distribution and more than one third (35.5%) of non-NIP vaccines. Another distribution mode was occupied as fully buying the service from third parties in 3 municipalities. Some provinces mixed both modes, too. The total distribution volume of vaccines was 430.7 million doses in 2018. The top five non-NIP vaccines delivered in 2018 were human rabies vaccine, varicella vaccine, EV71 hand foot mouth disease vaccine, hepatitis B vaccine and influenza vaccine. The vaccine biding, procurement and distribution management varied over provinces in mainland China in 2018, especially for non-NIP vaccines. Specific policies and measures should be developed for different regions to improve the immunization management better. [ABSTRACT FROM AUTHOR]

Live attenuated vaccines are contraindicated for patients on immunosuppressive agents or biological agent, except for live attenuated varicella vaccine, although previous reports showed their effectiveness and safety. This study is the nationwide cross-sectional research about the current utilization of live attenuated vaccines for patients on immunosuppressive agents or biological agents in Japan. We sent questionnaires to pediatric centers and examined whether each institution offered live attenuated vaccines to patients with immunosuppressive agents or biological agents (institutional research). We also examined adverse events associated with live attenuated vaccines between 2013 and 2017 (patient research). In the institutional research, 46 out of 334 institutions (13.8%) administered live attenuated vaccines to patients receiving immunosuppressive agents. In contrast, only six out of 270 institutions (2.2%) administered live attenuated vaccines to patients receiving biological agents. However, 66.3% of physicians answered that patients receiving immunosuppressive agents should be immunized with live attenuated vaccines, and only 7.0% disagreed with them. In the patient research, data for 781 patients were collected. Vaccine-associated infections were observed in only two patients (0.3%), both of whom had varicella, although they recovered promptly. No life-threatening adverse events were noted. Conclusion: In pediatric centers, the demand for live attenuated vaccines in patients receiving immunosuppressive agents was high and most physicians think they should be immunized. Immunization with live attenuated vaccines appeared safe in patients receiving immunosuppressive agents, although further studies are needed for patients receiving biological agents What is known: • Live attenuated vaccines (LAV) are generally contraindicated for patients on immunosuppressive agents (IS) or biological agents (BA), except for live attenuated varicella vaccine, as immunocompromised patients are at greater risk for serious viral infection from the vaccine strains. • Viral infections, such as measles and varicella, cause serious complications in children receiving IS. • Several previous reports showed that LAV is relatively effective and safe for patients receiving IS. What is new: • In Japan, the demand for LAV in patients receiving IS was high, and most physicians hoped they should be immunized. • Vaccine-associated infection is rarely observed in patients with IS after LAV administration. • Immunization with LAV appeared safe in patients receiving IS. Trial registration: University Hospital Medical Information Network (UMIN). Trial registration number: UMIN000029176. Date of registration: 2017/09/19. [ABSTRACT FROM AUTHOR]

• No effect of HIV exposure on immunogenicity of hepatitis-A and varicella vaccines. • Most children were seropositive after single dose hepatitis-A vaccine. • Less than half seroconverted after one dose of varicella vaccine. HIV-exposed uninfected (HEU) children have increased risk of infectious morbidity during early childhood. We evaluated the short-term immunogenicity and safety of single dose inactivated hepatitis-A virus (HAV) vaccine and live attenuated varicella zoster virus (VZV) vaccine in South African children. 195 HIV-unexposed and 64 HEU children received either one dose of HAV or VZV vaccine at 18 months of age. Blood samples were tested for hepatitis-A or VZV antibodies before and one month after vaccination by chemiluminescent microparticle immunoassay and enzyme-linked immunosorbent assay, respectively. All children were evaluated for solicited adverse events (AEs). One-month post-vaccination, a similar percentage of HIV-unexposed (91.8%) and HEU (82.9%) children were seropositive for hepatitis-A (p = 0.144). VZV antibody geometric mean fold-rise was also similar in HIV-unexposed (5.6; 95%CI: 4.6–6.7) and HEU children (5.1; 95%CI: 3.7–7.2); however, only 44% HIV-unexposed and HEU seroconverted (titers > 50 mIU/ml). AEs occurred with similar frequency and severity between groups, except for more systemic AEs after VZV vaccination in HEU than HIV-unexposed children. Single dose HAV and VZV vaccine was similarly immunogenic in HIV-unexposed and HEU children. We did not identify differences in short-term humoral immunity after administration of either a live attenuated or inactivated vaccine. Seroconversion rates after a single dose of VZV vaccine were, however, lower compared to reports from previous studies (85–89%). Clinical trials registration: NCT03330171. [ABSTRACT FROM AUTHOR]

Objective: Although there is no mandatory vaccination schedule for health care workers in Turkey, several vaccines such as seasonal influenza, tetanus, hepatitis B, measles-mumps-rubella (MMR), and varicella vaccines are recommended for all healthcare professionals. This study aimed to determine the attitudes and behaviors of health care workers to the recommended vaccines for themselves. Methods: The universe of cross-sectional study was 488 physicians and nurses working at the Faculty of Medicine, Pamukkale University. The participation rate was 88.6%. Participants' sociodemographic characteristics, their attitudes to vaccines required for themselves and behaviors towards vaccination were questioned by a questionnaire. Descriptive statistics, χ², Mann- Whitney U and Kruskal-Wallis tests were used in data analysis and multiple analyzes were performed. Results: The mean (±SD) of the attitude score was 19.9±2.5. The rate of having seasonal influenza vaccination every year was 4.8%; the ratio of triple dose hepatitis B and tetanus vaccination was 82.9% and 67.4%, respectively. The ratio of two doses of MMR and varicella vaccination was 56.0% and 40.8%, respectively. Being a resident (OR: 9.7, 95% CI: 3.0-31.9, p<0.001) or a nurse (OR: 12.4, 95% CI: .4-34.7, p<0.001) were risk factors for not having seasonal influenza vaccine every year. For not completing the 3-dose hepatitis B vaccine series, the attitude score against vaccination (OR: 0.8, 95% CI: 0.8-0.9, p=0.005) was a protective factor, while being a nurse (OR: 2.2, 95% CI: 1.1-4.08, p=0.012) or a faculty member (OR: 3.3, 95% CI: 1.4-7.4, p=0.004) was a risk factor. For not completing the 2-dose MMR vaccine series, being a nurse (OR: 2.2, 95% CI: 1.5-3.3, p<0.001) and age (OR: 1.06, 95% CI: 1.04-1.09, p<0.001) were risk factors. For not completing 2-dose varicella vaccine series, age (OR: 1.08, 95% GA: 1.05-1.1, p<0.001) and having no individual over 65 years at home (OR: 2.2, 95% GA: 1.06-4.85, p=0.035) were risk factors. Conclusions: Although the health care workers' attitudes to vaccines required for themselves and behaviors towards vaccination are positive, their vaccination rates are not at the desirable levels. More studies to determine the reasons that lead to low vaccination rates of health workers are needed. [ABSTRACT FROM AUTHOR]

Determination of Varicella vaccine's potency; containing live attenuated strain (Oka) of Varicella Zoster virus, has been limited to in vitro cell culture methods. In this study, a label free potentiometric biosensor has been developed for the first time and optimized to determine the content of varicella zoster virus. A passive ion-flux sensing platform has been developed using an anti-varicella monoclonal antibody and tetrabutyl ammonium bromide as a marker ion. The immunosensor has been optimized with respect to membrane diameter and concentration of the immobilized antibody. Linearity was achieved over a concentration range of 2.5–3.2 log PFU/dose with a LOD of 1.9 log PFU/dose. Potentiometric results were compared to the plaque-forming assay using the cell culture technique. The developed immunosensor was superior with respect to analysis time and cost without affecting critical analytical performance characteristics. Furthermore, in order to evaluate the stability indicating ability of the immunosensor, the effect of pH and temperature was investigated. Vaccine samples were subjected to forced degradation conditions; pH and elevated temperatures. Stability results showed the ability of immunosensor to differentiate between intact and degraded viral content. This would demonstrate the reliability of the immunosensor for evaluating the efficacy and stability of the vaccine. [Display omitted] • A label free potentiometric immunosensor was optimized to determine varicella zoster virus applying ion-flux approach. • Potentiometric results were found comparable to the results of the compendial cell based method. • The critical performance parameters of the biosensor were validated according to FDA guidelines. • Stability study demonstrated the ability of the immunosensor to differentiate between intact and degraded virus content. • The performed study illustrated the applicability of the immunosensor for quality control and batch release purposes. [ABSTRACT FROM AUTHOR]

To determine whether immunogenicity of the herpes zoster live-attenuated vaccine (ZVL) in elderly individuals is influenced by frailty status and cytokine levels, individuals aged at least 65 years were prospectively administered ZVL after their frailty status and cytokine levels were assessed. Humoral and cellular immunogenicity were assessed using enzyme-linked immunosorbent assays for the varicella-zoster virus-specific IgG antibody and varicella-zoster virus-specific enzyme-linked immunospot assays, before and 6 weeks after vaccination. We enrolled 69 participants (mean age, 74.3 years); 31 were non-robust. Thirty-seven participants had a greater than 2 geometric mean fold rise in IgG antibodies, 22 more participants had at least 10 spot-forming cells/106 peripheral blood mononuclear cells (from 35 to 57 participants), and 42 experienced a twofold geometric mean fold rise increase of spot-forming cells 6 weeks after vaccination. The geometric mean fold rises of the antibody titers were similar in the robust and non-robust groups; moreover, the baseline enzyme-linked immunospot assay geometric mean values were not significantly different before or 6 weeks after vaccination. We observed no significant correlations between baseline cytokine levels and immunogenicity. Approximately half of the community-dwelling elderly participants in this study experienced a twofold rise in antibodies and one-third more participants showed at least 10 spot-forming cells after ZVL administration, suggesting that the ZVL can boost immunity in non-robust (especially pre-frail) and robust elderly individuals. [ABSTRACT FROM AUTHOR]

Historic herpes zoster incidence trends in US adults have been hard to interpret. Using administrative databases, we extended previous descriptions of these trends through 2016. We observed an age-specific transition, with ongoing increases among younger adults but deceleration in older adults. The patterns are not readily explained. [ABSTRACT FROM AUTHOR]