Search

O objetivo deste estudo foi avaliar a Taxa de Mortalidade Infantil (TMI) pela utilização do método de linkage entre o banco de dados do Sistema de Informação sobre Nascidos Vivos (SINASC) e sobre mortalidade (SIM) e compará-la com a encontrada nos dados brutos fornecidos pelas mesmas bases de dados. Foi utilizado o SINASC contendo 9.590 Declarações de Nascidos Vivos (DNV) entre 1º de janeiro e 31 de dezembro de 2005 e o SIM com 156 Declarações de Óbitos (DO) relativas à população estudada. Dos 156 óbitos relativos ao ano de 2005 foram pareados pelo método direto 126 (80,8%) e pelo método de busca manual 11 (7%), totalizando um total de 137 óbitos (87,8%). As taxas encontradas com o método de linkage permitiram estimar a real TMI (14,2 óbitos/1.000 nascidos vivos) e a de seus componentes. A TMI encontrada pelo uso do método de linkage foi 17,3% menor que a calculada peça utilização dos registros brutos do SIM, permanecendo o componente neonatal precoce (7,2 óbitos/1.000 nascidos vivos) como o principal responsável pelos óbitos no primeiro ano de vida (50,4%).This study aimed to analyze the infant mortality rate (IMR) by linking the Live Birth Information System (SINASC) and the Mortality Information System (SIM) and comparing the result to direct calculation using crude data provided by the same databases. The systems used were SINASC, containing 9,590 certificates of live birth from January 1 to December 31, 2005, and SIM, containing 156 death certificates from the reference population (2005). Of the 156 deaths in the year 2005, 126 (80.8%) were paired by the direct method and 11 (7%) by manual search, totaling 137 deaths (87.8%). The rates found with the linkage method allowed calculating the real IMR (14.2 deaths/1,000 live births) and its components. The IMR using linkage was 17.3% lower than as calculated using crude SIM data. The early neonatal component (7.2 deaths/1,000 live births) accounted for half of the deaths in the first year of life (50.4%).

JE-CV (IMOJEV®, Sanofi Pasteur, France) is a live attenuated virus vaccine constructed by inserting coding sequences of the prM and E structural proteins of the Japanese encephalitis SA14-14-2 virus into the genome of yellow fever 17D virus. Primary immunization with JE-CV requires a single dose of the vaccine. This article reviews clinical trials of JE-CV in children aged up to 6 years conducted in countries across South-East Asia. Strong and persistent antibody responses were observed after single primary and booster doses, with 97% of children seroprotected up to five years after booster vaccination. Models of long-term antibody persistence predict a median duration of protection of approximately 30 years after a booster dose. The safety and reactogenicity profiles of JE-CV primary and booster doses are comparable to other widely used childhood vaccines. [ABSTRACT FROM PUBLISHER]

Background: Recent outbreaks between 2015-17 and production delays have led to a yellow fever vaccine shortage. Therefore, there is an urgent need for new yellow fever vaccines with improved production scalability. A next-generation live-attenuated yellow fever vaccine candidate (vYF), produced in a Vero cell line has shown similar immunogenicity to licensed yellow fever vaccines in preclinical studies. In this study, we aimed to report the safety and immunogenicity of vYF in human clinical trial participants., Methods: In this first in-human, phase 1 randomised, observer-blind, active-controlled, dose-ranging clinical trial conducted at a single centre in the USA (Walter Reed Army Institute of Research, Silver Spring, MD, USA), 72 healthy adults (aged 18-60 years), without a known history of flavivirus infection or vaccination were randomly assigned (1:1:1:1) using interactive response technology to receive one dose of either vYF at 4, 5 or 6 Log CCID 50 or the licensed YF-VAX (18 individuals per group). The primary outcomes were safety, neutralising antibody (NAb) titres through D180 post-vaccination in the per-protocol analysis set (comprised of yellow fever-naive participants who received their intended vaccine and provided a valid post-vaccination blood sample), and occurrence, and level of yellow fever viraemia in each vaccine group through D14 post-vaccination., Findings: All vYF doses had a safety and tolerability profile similar to YF-VAX. The most frequently reported solicited injection site reactions (vYF groups vs YF-VAX group) were pain (22% [12 of 54 participants, 95% CI 12-36] vs 28% [five of 18 participants, 10-54]), and erythema (13% [seven of 54 participants, 5-25] vs 39% [seven of 18 participants, 17-64]), with headache (32% [17 of 54 participants, 20-46] vs 44% [eight of 18 participants, 22-69]) and malaise (26% [14 of 54 participants, 15-40] vs 33% [six of 18 participants, 13-59]) as the most frequently reported solicited systemic reactions. One grade 3 solicited reaction (erythema) reported in the YF-VAX group resolved spontaneously. No serious unsolicited adverse events or deaths were reported. Viraemia was transiently detected in 50 participants between D4 and D10 in all groups and was observed in more participants or for a longer time in the vYF 6 Log CCID 50 and YF-VAX groups. All yellow fever-naive vaccine recipients across the study groups seroconverted yielding four-fold increase from baseline in yellow fever NAb titres measured by yellow fever microneutralisation assay by D28 and were seroprotected with yellow fever NAb titres of at least 10 [1/dil]). Overall, 100% (18 of 18 participants, 95% CI 82-100), 89% (16 participants, 65-99), 100% (18 participants, 82-100), and 94% (17 participants, 73-100) of participants in the vYF 4 Log, vYF 5 Log, vYF 6 Log CCID 50 groups, and YF-VAX group, respectively, remained seroprotected through D180., Interpretation: vYF has a similar safety and immunogenicity profile to YF-VAX. In general, the vYF 5 Log CCID 50 dose appeared to show optimal viraemia, safety, and immunogenicity, and was chosen for subsequent development., Funding: Sanofi., Competing Interests: Declaration of interests A-MM, HA, YW, ARP, VD, NM, MV, and EF are Sanofi employees and hold shares and stock options in the company. KM and PTS were employed by the Walter Reed Army Institute of Research at the time of this study. MM, BO-S, ES, MFA, APP, BO, MNM, KSK, MEM, IG, MEG, JMD, MAK, MJH, CEL, JNH, SAP, and MLR received funds from Sanofi through their institutions to support their work in the VYF01 trial (NCT04142086)., (Copyright © 2024 Elsevier Ltd. All rights reserved, including those for text and data mining, AI training, and similar technologies.)

Background: Yellow fever (YF), a mosquito-borne acute viral haemorrhagic illness, is endemic to many tropical and subtropical areas of Africa and Central and South America. Vaccination remains the most effective prevention strategy; however, as repeated outbreaks have exhausted vaccine stockpiles, there is a need for improved YF vaccines to meet global demand. A live-attenuated YF vaccine candidate (referred to as vYF) cloned from a YF-17D vaccine (YF-VAX®) sub-strain, adapted for growth in Vero cells cultured in serum-free media, is in clinical development. We report the innate and adaptive immune responses and the transcriptome profile of selected genes induced by vYF., Methods: Healthy adults aged 18-60 years were randomised at a 1:1:1:1 ratio to receive one dose of vYF at 4, 5 or 6 Log CCID 50 or YF-VAX (reference vaccine), administered subcutaneously in the upper arm (ClinicalTrials.gov identifier: NCT04142086). Blood/serum samples were obtained at scheduled time points through 180 days (D180) post-vaccination. The surrogate endpoints assessed were: serum cytokine/chemokine concentrations, measured by bead-based Multiplex assay; peripheral blood vYF-specific IgG and IgM memory B cell frequencies, measured by FluoroSpot assay; and expression of genes involved in the immune response to YF-17D vaccination by RT-qPCR., Findings: There was no increase in any of the cytokine/chemokine concentrations assessed through D14 following vaccination with vYF or YF-VAX, except for a slight increase in IP-10 (CXCL10) levels. The gene expression profiles and kinetics following vaccination with vYF and YF-VAX were similar, inclusive of innate (antiviral responses [type-1 interferon, IFN signal transduction; interferon-stimulated genes], activated dendritic cells, viral sensing pattern recognition receptors) and adaptive (cell division in stimulated CD4+ T cells, B cell and antibody) immune signatures, which peaked at D7 and D14, respectively. Increases in vYF-specific IgG and IgM memory B cell frequencies at D28 and D180 were similar across the study groups., Interpretation: vYF-induced strong innate and adaptive immune responses comparable to those induced by YF-VAX, with similar transcriptomic and kinetic profiles observed., Funding: Sanofi., Competing Interests: Declaration of interests AP, CC, MA, EC, SG, FR, EF, MV, and NM are Sanofi employees and hold shares and/or stock options in the company. PS and KM received funds from Sanofi through their institution (WRAIR) to support their work in the vYF01 trial. The opinions expressed herein are those of the authors and should not be construed as official or representing the views of the US Department of Defense or the Department of the Army., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Vaccines prevent infectious diseases, but vaccination is not without risk and adverse events are reported although they are more commonly reported for biologicals than for vaccines. Vaccines and biologicals must undergo vigorous assessment before and after licensure to minimise safety concerns. Potential safety concerns should be identified as early as possible during the development for vaccines and biologicals to minimize investment risk. State-of-the art tools and methods to identify safety concerns and biomarkers that are predictive of clinical outcomes are indispensable. For vaccines and adjuvant formulations, systems biology approaches, supported by single-cell microfluidics applied to translational studies between preclinical and clinical studies, could improve reactogenicity and safety predictions. Next-generation animal models for clinical assessment of injection-site reactions with greater relevance for target human population and criteria to define the level of acceptability of local reactogenicity at vaccine injection sites in pre-clinical animal species should be assessed. Advanced in silico machine-learning-based analytics, species-specific cell or tissue expression, receptor occupancy and kinetics and cell-based assays for functional activity are needed to improve pre-clinical safety assessment of biologicals. The in vitro MIMIC® system could be used to compliment preclinical and clinical studies for assessing immune-toxicity, immunogenicity, immuno-inflammatory and mode of action of biologicals and vaccines. Sanofi Pasteur brought together leading experts in this field to review the state-of-the-art at a unique 'Safety Biomarkers Symposium' on 28-29 November 2017. Here we summarise the proceedings of this symposium. This unique scientific meeting confirmed the importance for institutions and industrial organizations to collaborate to develop tools and methods needed for predicting reactogenicity and immune-inflammatory reactions to vaccines and biologicals, and to develop more accuracy, reliability safety biomarkers, to inform decisions on the attrition or advancement of vaccines and biologicals., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020.)

The live-attenuated Japanese encephalitis chimeric virus vaccine JE-CV (IMOJEV®, Sanofi Pasteur) elicits a robust antibody response in children, which wanes over time. Clinical efficacy is based on a correlate of protection against JE infection defined as neutralizing antibody levels equal to or greater than the threshold of 10 (1/dil). Information on the duration of persistence of the JE antibody response above this threshold is needed. We constructed statistical models using 5-year persistence data from a randomised clinical trial (NCT00621764) in children (2-5 years old) primed with inactivated JE vaccine who received a booster dose of JE-CV, and in JE-naïve toddlers (12-24 months) who received a JE-CV single dose primary vaccination. Models were constructed using a Bayesian Monte-Carlo Markov Chain approach and implemented with OpenBugs V3.2.1. Antibody persistence was predicted for up to 10 years following JE-CV vaccination. Findings from a piecewise model with 2 phases (children) and a classic linear model (toddlers) are presented. For children, predicted median antibody titers (77 [2.5th-97.5th percentile range 41-144] 1/dil) remained above the threshold for seroprotection over the 10 years following booster JE-CV vaccination; the predicted median duration of protection was 19.5 years. For toddlers, 10 years after JE-CV primary vaccination median antibody titers were predicted to wane to around the level required for seroprotection (10.8 [5.8-20.1] 1/dil). A booster dose of JE-CV in children is predicted to provide long-term protection against JE. Such data are useful to facilitate decisions on implementation of and recommendations for future vaccination strategies.

Objective: Antibody persistence evaluation for all antigens of a fully liquid DTaP-IPV-HB-PRP~T vaccine at 3.5 and 4.5 y of age following different primary series and booster schedules in South Africa and Latin America., Methods: Participants had completed one of two previous studies (Study 1-South Africa; Study 2-Latin America). In Study 1, participants who had not received HB vaccine at birth received a 6-10-14 week primary series of DTaP-IPV-HB-PRP~T or DTwP/PRP~T-Hib+HB+OPV and a third group who had received HB vaccine at birth received a 6-10-14 week primary series of DTaP-IPV-HB-PRP~T; all received a booster (15-18 months) of the primary series vaccine(s) except for HB in the DTwP/PRP~T-Hib group. In Study 2, participants received HB vaccine at birth, a 2-4-6 month primary series of DTaP-IPV-HB-PRP~T or DTaP-HB-IPV//PRP~T, and a DTaP-IPV-HB-PRP~T or DTaP-HB-IPV//PRP~T booster (12-24 months). Participants were followed up at 3.5 and 4.5 y of age for antibody persistence., Results: Approximately 80% of eligible participants were assessed. In Study 1, a birth dose of HB increased anti-HBs persistence (≥10 mIU/mL) following DTaP-IPV-HB-PRP~T primary and booster vaccination from 76.3% to 96.1% at 3.5 y of age and from 73.3% to 96.1% at 4.5 y of age; in Study 2, anti-HBs persistence was high and similar in each group. For the other antigens, there were no differences between groups or studies at 3.5 or 4.5 y., Conclusion: Good persistence of antibodies to each antigen in the DTaP-IPV-HB-PRP~T vaccine up to pre-school age, irrespective of the vaccination schedule during the first 2 y of life.

To support a fully liquid, diphtheria (D)-tetanus (T)-acellular pertussis (aP)-inactivated poliovirus (IPV)-hepatitis B (HB)-Haemophilus influenzae b (PRP-T) vaccine in Europe using a 2, 3, 4 month primary series and a booster at 11-15 months of age. Phase III, randomized, observer-blind studies in Germany and the Czech Republic. Participants who had not received HB vaccine were randomized to a 2, 3, 4 month primary series of DTaP-IPV-HB-PRP-T (group 1; N = 266) or a reconstituted DTaP-HB-IPV//PRP-T comparator (group 2; N = 263) and a booster of the same vaccine. Pneumococcal vaccine (PCV13) and rotavirus vaccine were coadministered at 2, 3, 4 months, and the booster was coadministered with PCV13. Noninferiority (group 1 versus group 2) was tested postprimary series for seroprotection rates (anti-HB and anti-PRP) and vaccine response rates (anti-pertussis toxin and anti-filamentous hemagglutinin). Safety was assessed by parental reports. Noninferiority was demonstrated with the lower bound of the 95% confidence interval for the difference (group 1 to group 2) being > -10% for each comparison. Primary series immune responses were high for all antigens and similar in each group. Prebooster antibody persistence was good, and there was a strong anamnestic response, both being similar for the investigational and control vaccines. Responses to PCV13 and rotavirus vaccine were similar in each group. There were no safety concerns. These data support the use of the DTaP-IPV-HB-PRP-T vaccine in a 2, 3, 4 month schedule without a birth dose of HB vaccine, with a booster dose in the second year of life administered with routine childhood vaccines.

Clinical Trials Registration: NCT01190228., (© The Author(s) 2018. Published by Oxford University Press for the Infectious Diseases Society of America.)

Background: Hexavalent diphtheria-tetanus-acellular pertussis-inactivated poliovirus-hepatitis B-Haemophilus influenzae type b (DTaP-IPV-HB-PRP-T)-containing vaccines are increasingly the standard of care. This study evaluated the primary series (NCT01177722) and booster (NCT01444781) of a fully liquid DTaP-IPV-HB-PRP-T vaccine in Latin America., Methods: Infants (N = 1375) received hepatitis B vaccine at birth and were randomized to one of 3 batches of the investigational DTaP-IPV-HB-PRP-T or licensed control vaccine (DTaP-HB-IPV//PRP-T) at 2-4 to 6 months of age, coadministered with 7-valent pneumococcal conjugate vaccine (PCV7) (2-4-6 months) and rotavirus vaccine (2-4 months). A booster of either DTaP-IPV-HB-PRP-T or control was given at 12-24 months, coadministered with PCV7. Immunogenicity was assessed by validated assays and safety from parental reports., Results: Primary series seroprotection and vaccine response rates were equivalent for DTaP-IPV-HB-PRP-T batches. For pooled batches, noninferiority to the control vaccine was demonstrated for each antigen. There were no descriptive differences in antibody persistence or booster response between DTaP-IPV-HB-PRP-T and the control. The booster responses to either vaccine following DTaP-IPV-HB-PRP-T primary series or to DTaP-IPV-HB-PRP-T following a control vaccine primary series were similar. The anti-aP component (filamentous hemagglutinin [FHA] and pertussis toxin [PT]) vaccine response and anti-Haemophilus influenzae type b (PRP) series seroprotection (≥0.15 µg/mL) rates were ≥73.0% after 2 primary series doses. Antipyretics had no effect on the immune response, and an extra (oral) polio vaccination had no effect on the antipolio booster response. Responses to PCV7 and rotavirus vaccine were similar for each coadministration. There were no safety concerns observed with any vaccine., Conclusions: These results confirm the suitability of the fully liquid DTaP-IPV-HB-PRP-T vaccine for primary and booster vaccination of infants.

Background/aim: Immunogenicity and safety of a primary series of a fully liquid, hexavalent DTaP-IPV-HB-PRP-T vaccine given at 2, 3, and 4 months of age compared to licensed comparators and a DTaP-IPV-HB-PRP-T booster at 15?18 months were evaluated. Materials and methods: This was a Phase III, randomized, open-label trial. Primary series (no hepatitis B [HB] at birth) of DTaP-IPV-HB-PRP-T (N = 155) (group 1) or licensed control vaccines (DTaP-IPV//PRP-T and standalone HB: N = 155) (group 2) and DTaP-IPV-HB-PRP-T booster were administered. Noninferiority was evaluated 1 month postprimary series for anti-HB seroprotection (SP). All other analyses were descriptive. Safety was assessed from parental reports. Results: Postprimary series noninferiority of anti-HB ≥ 10 mIU/mL was demonstrated for the DTaP-IPV-HB-PRP-T vaccine (94.0%) compared to the licensed control (96.1%). Postprimary series primary SP and seroconversion (SC) rates were high and similar for both groups. Antibody persistence (prebooster) was high for each antigen and similar between groups except for HB, which was lower for DTaP-IPV-HB-PRP-T than for standalone HB. For each antigen except HB, DTaP-IPV-HB-PRP-T booster responses were high and similar in each group. Safety was good for primary and booster series and similar between groups. Conclusion: The DTaP-IPV-HB-PRP-T vaccine is immunogenic and safe when administered in a challenging primary series schedule without HB vaccination at birth.

Background: Japanese encephalitis (JE) is an important mosquito-borne viral disease that is endemic in Asia, Western Pacific countries and Northern Australia. Although there is no antiviral treatment, vaccination is effective in preventing this disease., Methods: We followed a cohort of 596 children for 5 years after primary vaccination at 12-18 months of age with JE chimeric virus vaccine (JE-CV; IMOJEV) in a multicenter, phase III trial in Thailand and the Philippines to assess antibody persistence and safety. At the end of the 5 years, a subgroup of 85 participants, at 1 site in Thailand, was followed after administration of a JE-CV booster vaccination. JE antibody titers were measured annually after primary vaccination and 28 days after booster vaccination using a 50% plaque reduction neutralization test. Seroprotection was defined as a JE-CV neutralizing antibody titer ≥10 (1/dil). Kaplan-Meier survival analysis was used to estimate the proportion of participants maintaining protective JE-CV neutralizing antibody titers., Results: At 1, 2, 3, 4 and 5 years after vaccination with JE-CV, 88.5%, 82.9%, 78.2%, 74.0% and 68.6% of the participants followed remained seroprotected. Geometric mean titers in the subgroup assessed after receipt of a booster dose increased from 61.2 (95% confidence interval: 43.8-85.7) pre-booster to 4951 (95% confidence interval: 3928-6241) 28 days post-booster, with all participants seroprotected. There were no safety concerns identified., Conclusions: Protective immune responses persisted for at least 5 years after a JE-CV primary immunization in the majority of participants. JE-CV booster induced a robust immune response even after a 5-year interval.

Background: The live-attenuated Japanese encephalitis (JE) vaccine (JE-CV; IMOJEV) induces a protective response in children. A shift in circulating JE virus strains suggests that a genotype shift phenomenon may occur throughout Southeast Asia. We assessed the neutralization of wild-type (WT) JE virus isolates at distal time points after vaccination., Methods: We analyzed serum samples from a subset of 47 children who had received a JE-CV booster after an inactivated JE vaccine primary immunization. We measured antibody titers (50% plaque reduction neutralization test) using a panel of WT JE strains at baseline, then after the booster at 28 days and 6 months in all subjects present at the time points and in a subset at year 5. Three additional recent isolates were tested at year 5., Results: Of 47 subjects, 43 (91.5%) subjects had JE neutralizing antibody titers ≥10 (reciprocal serum dilution) against the homologous strain before JE-CV boost; all were seroprotected up to year 5 after the JE-CV boost. Baseline WT seroprotection ranged between 78.7% and 87.2%; all subjects were seroprotected against the 4 WT strains at 28 days and 6 months; year 5 seroprotection ranged between 95.7% and 97.9%. Similar rates of protection against 3 additional WT isolates were observed at year 5., Conclusions: The long-term immune responses induced after a JE-CV booster dose in toddlers were able to neutralize WT viruses from various genotypes circulating in Southeast Asia and India., Clinical Trials Registration: NCT00621764., (© The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America)

Background: To assess the immunogenicity and safety of a fully liquid, ready-to-use hexavalent DTaP-IPV-HB-PRP-T vaccine when administered in a 2 + 1 schedule at 3, 5 and 11-12 months of age., Methods: Phase III, randomized, active-controlled, observer-blind, multicenter study. Infants were randomized to receive DTaP-IPV-HB-PRP-T (N = 275) or a licensed control hexavalent vaccine (DTaP-IPV-HB//PRP~T: N = 275), both given in coadministration with Prevenar 13. Serum was analyzed for immune responses to all vaccine antigens. Noninferiority of DTaP-IPV-HB-PRP-T to the control vaccine was tested at completion of the primary series using predefined seroprotection (SP) rate and vaccine response (VR) rates. Safety was assessed using parental reports., Results: Noninferiority of DTaP-IPV-HB-PRP-T to the control vaccine was demonstrated postdose 3 for each antigen, and the SP (for D, T, poliovirus 1, 2 and 3, hepatitis B and polyribosylribitol phosphate) and VR rates (for pertussis toxin and filamentous hemagglutinin) were high in each group. SP rates for D, T, polio 1, 2, 3 and VR rates for pertussis toxin and filamentous hemagglutinin were similar in each group. For hepatitis B, SP rate was slightly higher for DTaP-IPV-HB//PRP~T (99.6%) than DTaP-IPV-HB-PRP-T (96.4%), and for PRP, SP rate was higher for DTaP-IPV-HB-PRP-T (93.5%) than DTaP-IPV-HB//PRP~T (85.2%). For Prevenar 13, the SP rate was high for each serotype and similar for both groups. All vaccines were well tolerated., Conclusions: These study findings confirm the safety and immunogenicity and thus the suitability of this fully liquid hexavalent vaccine for administration in a 2 + 1 schedule.

Background: A single dose of live attenuated Japanese encephalitis chimeric virus vaccine (JE-CV) was shown to be immunogenic and well tolerated when given either as a booster to formalin-inactivated Japanese encephalitis (JE)-vaccine (mouse brain-derived vaccine [MBDV])-primed 2-5-year-olds, or as a primary vaccination to JE-vaccine-naïve 12-24-month-old toddlers in Thailand. A 5-year follow-up assessment of immune response persistence over time was conducted., Methods: Four additional visits (at 2, 3, 4, and 5years) for immunologic assessments were added to the original 12-month open-label crossover study, in which 100 healthy children aged 2-5years with a history of two-dose primary vaccination with MBDV (according to the Thai Expanded Program for Immunization schedule), and 200 healthy JE-vaccine-naïve 12-24-month-old toddlers, were randomized 1:1 to receive JE-CV, containing ⩾4 log 10 plaque forming units, 1month before or after hepatitis A control vaccine., Results: In MBDV-primed 2-5-year-olds (n=78), the immune response to the JE-CV vaccine persisted up to at least 5years after vaccination with a single dose of JE-CV, with all (n=78) children seroprotected at the year 5 visit (geometric mean titers [GMT]: 2521/dil). There was no decrease of seroprotection rate over time (100% at 6months post-vaccination and 96.8% (90.3-98.9) at 5yearspost-vaccination). In JE-vaccine-naïve toddlers, a protective immune response persisted up to at least 5years in 58.8% (50.9-66.4) after a single-dose administration of JE-CV (GMT 26.71/dil; sensitivity analysis)., Conclusions: A single-dose of JE-CV as a booster following MBDV administration provided long-lasting immunity. In JE-vaccine-naïve toddlers, despite relatively high seroprotection rates persisting over time, a subsequent booster dose is recommended following a JE-CV primary vaccination for long-term protection. This study was registered on www.clinicaltrials.gov (NCT00621764)., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Background: Japanese encephalitis (JE) is the most important cause of viral encephalitis in Asia., Methods: In this randomized, open-label, multicenter trial in 550 children aged 12 to 18 months in Taiwan, children received one dose of JE-CV and one dose of MMR vaccine. Vaccines were either administered separately 6 weeks apart (Groups 'JE-CV' and 'MMR', named after which vaccine was given first), or concomitantly (Group 'Co-Ad'). JE neutralizing antibody titers were assessed using PRNT50. MMR antibody levels were determined by ELISA., Results: All groups had low seroprotection/seropositivity rates (<10%) before vaccination for all antigens. Forty two days after vaccination, on either Study Day 42 or 84, seroconversion rates for all antigens were high in all groups, irrespective of the order of vaccinations. Seroconversion for JE ranged from 96.9% in Group Co-Ad on D42 to 100% in Group MMR. Non-inferiority was demonstrated for all analyses as the lower bound of the 95% CI of the difference in seroconversion rates between groups was above the pre-defined limit of -10.0%. The immune responses remained high for all antigens and well above the level of protection 12 months after vaccination in all groups. There were no safety concerns., Conclusions: JE-CV is safe and induces a strong protective immune response which persists over 1 year when co-administered with MMR vaccine., (Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: The live, attenuated Japanese encephalitis (JE) chimeric virus vaccine (JE-CV) is licensed in Thailand and Australia for prophylaxis of JE in individuals at the age of 12 months. JE-CV has not yet been compared with the SA14-14-2 JE vaccine, which is also licensed in Thailand., Methods: In this phase 3, observer-blinded trial, 300 children at the age of 9-18 months were randomized 1:1 to receive 1 dose of JE-CV or SA14-14-2. JE neutralizing antibody titers were assessed using PRNT50. The primary endpoint was the noninferiority of seroconversion against JE on Day 28 after JE-CV compared with SA14-14-2, as assessed using the 95% confidence interval of the difference between the groups. Safety and reactogenicity were described in each group using conventional methods, including the reporting of solicited and unsolicited adverse events., Results: The seroconversion rate on Day 28 was 99.2% in each group. Noninferiority was demonstrated as the difference between the JE-CV and SA14-14-2 groups was -0.012 percentage points (95% confidence interval: -3.6 to 3.6), which was above the required -10%. The seroprotection rate remained very high at Month 6 and comparable between groups, but a slight decrease was observed in the JE-CV group between Months 6 and 12. Current recommendations for both vaccines call for a booster dose 12-24 months after primary immunization to maintain high seroprotection rates in the long term. Geometric mean titers (GMTs) on Day 28 after vaccination were 507 (1/dil) in the JE-CV group and 370 (1/dil) in the SA14-14-2 group, decreasing by 4.3-fold and 3.6-fold, respectively, to Month 6 before remaining stable to Month 12 and comparable between groups. Solicited reactions were all reported at lower rates after vaccination with JE-CV compared with SA14-14-2., Conclusions: A single dose of JE-CV elicited a noninferior immune response compared with SA14-14-2 and had a satisfactory safety profile.

Background: During clinical development of the licensed Japanese encephalitis chimeric virus vaccine (JE-CV), the neutralization capacity of vaccine-induced antibodies was assessed against the vaccine virus and against well characterized wild-type (wt) viruses isolated between 1949-1991. We assessed whether JE-CV-induced antibodies can also neutralize more recent wt Japanese encephalitis virus (JEV) isolates including a genotype 1 isolate., Methods: Sera from 12-18 month-old children who received a single dose of JE-CV in a phase III study in Thailand and the Philippines (ClinicalTrials.gov NCT00735644) were randomly selected and pooled according to neutralization titer against JE-CV into eight samples. Neutralization was assessed by plaque reduction neutralization tests (PRNT50) against three recent isolates from JEV genotypes 1 and 3 in addition to four JEV previously tested., Results: Neutralization titers against the three recent JEV strains were comparable to those observed previously against other strains and the vaccine virus. The observed differences between responses to genotype 1 and 3 viruses were within assay variability for the PRNT50., Conclusions: The results were consistent with previously generated data on the neutralization of wt JEV isolates, immune responses induced by JE-CV neutralize recently isolated virus from southeast (SE) Asia and India.

Japanese encephalitis chimeric virus vaccine (JE-CV) is a licensed vaccine indicated in a single dose administration for primary immunization. This controlled phase III comparative trial enrolled children aged 36-42 mo in the Philippines. 345 children who had received one dose of JE-CV in a study two years earlier, received a JE-CV booster dose. 105 JE-vaccine-naïve children in general good health were randomized to receive JE-CV (JE-vaccine naïve group; 46 children) or varicella vaccine (safety control group; 59 children). JE neutralizing antibody titers were assessed using PRNT50. Immunological memory was observed in children who had received the primary dose of JE-CV before. Seven days after the JE-CV booster dose administration, 96.2% and 66.8% of children were seroprotected and had seroconverted, respectively, and the geometric mean titer (GMT) was 231 1/dil. Twenty-eight days after the JE-CV booster dose seroprotection and seroconversion were achieved in 100% and 95.3% of children, respectively, and the GMT was 2,242 1/dil. In contrast, only 15.4% of JE-CV-vaccine naïve children who had not received any prior JE vaccine were seroprotected seven days after they received JE-CV. One year after receiving the JE-CV booster dose, 99.4% of children remained seroprotected. We conclude that JE-CV is effective and safe, both as a single dose and when administrated as a booster dose. A booster dose increases the peak GMT above the peak level reached after primary immunization and the antibody persistence is maintained at least one year after the JE-CV booster dose administration. Five year follow up is ongoing.

This trial in 1200 JE-vaccination naïve children (age 12-18 mo) in Thailand and the Philippines aimed to demonstrate consistency of three successive industrial scale manufacturing lots of live attenuated Japanese encephalitis chimeric virus vaccine (JE-CV) and consistency between industrial scale manufacturing lots and a fourth, development lot. Children received JE-CV from one of three successive industrial scale lots produced in Thailand (n = 899), or from a fourth development lot produced in the USA (n = 199), or hepatitis A control vaccine (n = 102). Antibodies were assessed by 50% plaque reduction neutralization test (PRNT(50)) at screening and Day 28. Seroconversion rates (titer of < 10 at baseline and ≥ 10 on Day 28, or a four-fold rise from a baseline titer of ≥ 10) were determined per group. Lot-to-lot consistency of seroconversion rate and GMT was demonstrated between the 3 industrial scale lots, and between these lots and the US lot. Seroconversion rate on pooled data 28 d after JE-CV vaccination (Thai lots) was 95.0% [95% confidence interval (CI); 93.3-96.3]. The safety profile of JE-CV was favorable and comparable with hepatitis A vaccine. There were no serious adverse events related to vaccination. This study demonstrated the consistency of three successive industrial scale JE-CV vaccine lots, as well as consistency with a development lot. The study also demonstrated that a single dose of JE-CV is well tolerated and elicits a high protective immune response, seroconverting 95% of JE-naïve Asian children aged 12-18 mo.

Background: Safe and effective Japanese encephalitis (JE) vaccines are needed to protect populations living in or visiting endemic areas. A live-attenuated JE-chimeric virus vaccine (JE-CV) has been developed with a single-dose regimen., Methods: In an open-label, crossover study, 100 children aged 2 to 5 years with a history of 2-dose primary vaccination with mouse-brain derived inactivated JE vaccine according to the Thai Expanded Program for Immunization schedule, and 200 JE vaccination-naive 12- to 24-month-old toddlers were randomized 1:1 to receive JE-CV, containing ≥4 log10 plaque forming units, 1 month before or after hepatitis A control vaccine. Neutralizing antibody titers were assessed using PRNT50 (titers expressed in inverse of dilution) before and 28 days after JE-CV, and at months 7 and 12., Results: All 2- to 5-year-olds and 96% of 12- to 24-month-olds were seroprotected (titer ≥10) 28 days after JE-CV administration, and geometric mean titers (GMT) (95% confidence interval) in these age groups were 2634 (1928-3600) and 281 (219-362), respectively. One year later, seroprotection rates in the 2 age groups were 97% and 84% and GMTs were 454 and 62.3, respectively. Vaccine-induced antibodies neutralized a panel of wild-type JE isolates. There were no vaccine-related serious adverse events. Reactogenicity of JE-CV was comparable with that of the inactivated hepatitis A vaccine., Conclusions: A single administration of JE-CV has a good safety profile and elicits a protective immune response in both JE-naive toddlers and JE-primed young children.

Japanese encephalitis chimeric virus vaccine (JE-CV) was developed to replace licensed mouse brain-derived vaccine (MBD-JE), the production of which ceased in 2005. Two randomised controlled phase 3 studies were conducted. Immunogenicity study: 410 participants received one JE-CV injection, 410 received 3 MBD-JE injections. Safety study: 1,601 participants received JE-CV, 403 received placebo. Seroconversion after a single JE-CV vaccination (99.1%) was statistically non-inferior to that after three-dose MBD-JE (95.1%) vaccination. JE-CV elicited a rapid immune response, with 93.6% of participants seroconverting within 14 days. Adverse reaction rates were significantly lower with JE-CV (67.6%) than with MBD-JE (82.2%) (p<0.001), and the reactogenicity profile of JE-CV was comparable with that of placebo. A single dose of JE-CV elicited rapid seroconversion in a higher proportion of vaccinees than the current vaccine with fewer reactions. The safety profile of JE-CV is good., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

A randomized, double-blind, study was conducted to evaluate the safety, tolerability and immunogenicity of a live attenuated Japanese encephalitis chimeric virus vaccine (JE-CV) co-administered with live attenuated yellow fever vaccine (YF-17D strain; Stamaril®, Sanofi Pasteur) or administered successively. Participants (n = 108) were randomized to receive: YF followed by JE-CV 30 days later, JE followed by YF 30 days later, or the co-administration of JE and YF followed or preceded by placebo 30 days later or earlier. Placebo was used in a double-dummy fashion to ensure masking. Neutralizing antibody titers against JE-CV, YF-17D and selected wild-type JE strains was determined using a 50% serum-dilution plaque reduction neutralization test. Seroconversion was defined as the appearance of a neutralizing antibody titer above the assay cut-off post-immunization when not present pre-injection at day 0, or a least a four-fold rise in neutralizing antibody titer measured before the pre-injection day 0 and later post vaccination samples. There were no serious adverse events. Most adverse events (AEs) after JE vaccination were mild to moderate in intensity, and similar to those reported following YF vaccination. Seroconversion to JE-CV was 100% and 91% in the JE/YF and YF/JE sequential vaccination groups, respectively, compared with 96% in the co-administration group. All participants seroconverted to YF vaccine and retained neutralizing titers above the assay cut-off at month six. Neutralizing antibodies against JE vaccine were detected in 82-100% of participants at month six. These results suggest that both vaccines may be successfully co-administered simultaneously or 30 days apart.

Children have a high risk of exposure to rabies in countries where the disease is endemic. This prospective, 5-year study followed two groups of children who had received diphtheria, tetanus, whole-cell pertussis and inactivated poliomyelitis vaccine (DTP-IPV) at 2, 3, 4 months and 1 year (Group B) or concomitant with three doses of purified Vero cell rabies vaccine (PVRV), given at 2, 4 months and 1 year (Group A). Antibody determinations were made annually for 5 years. Data were available from a total of 72 subjects; 30 in Group A and 32 in Group B. In Group A, the percentage of patients immunized against rabies (anti-rabies > or = 0.5 IU/ml) decreased from 100% after the third vaccination to 63%, 5 years later. After 5 years, 93.8% in Group A and 96.7% in Group B had seroprotective diphtheria antibody titers > or = 0.01 IU/ml, and all subjects had anti-polio (type 1, 2 and 3) seroprotective titers > or = 5 1:dil. We conclude that co-administration of PVRV with DTP-IPV elicited protective antibody concentrations to all antigens that persist for at least 5 years, with continued protection against rabies in over 60% of subjects. These results are consistent with integration of pre-exposure rabies vaccination into the Expanded Program on Immunization (EPI) in countries where rabies is endemic.

Vietnamese children received purified Vero cell rabies vaccine 1 year after a primary series (Y0) and again 5 years later (Y5), either as intramuscular or 1/5th dose intradermal injections concomitant with diphtheria, tetanus, pertussis and oral poliomyelitis vaccines. Antibody levels were assayed annually for 5 years. All subjects in both groups had anti-rabies antibody titres considered protective after the Y0 booster. Rabies seroprotection rates and geometric mean titres gradually decreased similarly in both groups. Seroprotection after the Y5 booster was 100% in both groups. Satisfactory immunogenicity, long-term antibody persistence and an anamnestic response were conferred by both routes, greatly simplifying any future post-exposure prophylaxis.