View clinical trials related to Encephalitis, Japanese.
Filter by:This is a single-arm, non-randomized, open-label post-marketing safety observation study. The purpose of this study is to investigate the safety of JEV-I given with primary immunization in a large amount of healthy children aged 8 months and older.
This is a phase IV, randomized, controlled, open-label study proceed in healthy children aged 8 months in China. The primary objective is to demonstrate the immunogenicity of simultaneous administration of JEV-I and MMR is not inferior to that of separate administration, as measured by seroconversion rates and antibody titers against the four antigens. The secondary objective is to describe the safety of the vaccines when administered simultaneously or separately.
Iron deficiency (ID) anaemia (IDA) is a global public health problem, with the highest prevalence in Africa and in South-East Asia. While immunization programs have achieved high global coverage, vaccines often underperform in low- and middle-income countries (LMIC). The cause remains uncertain, but undernutrition, including ID, likely plays a role. Our recent in vitro and in vivo studies have shown the importance of iron status in adaptive immunity and vaccine response. Hypoferremia blunted T cell, B cell, and neutralizing antibody responses to influenza virus infection in mice, allowing the virus to persist. Iron deficient anaemic Kenyan women receiving intravenous iron at time of vaccination had a better immune response to the first dose of the ChAdOx Coronavirus 19 (COVID-19) vaccine and yellow fever vaccine. Japanese encephalitis and typhoid fever are endemic in Thailand. Vaccines are available but show variable efficacy. Whether ID impairs adult vaccine response to the live attenuated Japanese encephalitis (JE) and the Typhoid Vi polysaccharide (Vi-PS) vaccine and whether iron repletion via iron fortification improves vaccine response is uncertain. The objective of this study is to assess whether IDA in Thai women impairs immune response to the JE and the Typhoid Vi-PS vaccine and whether fortification iron improves their response. In this double-blind randomized controlled trial, IDA women will be assigned to two study groups: group 1 (fortification group) will receive iron-fortified biscuits (15mg iron as ferrous fumarate) for 56 days; group 2 (control group) will receive non-fortified biscuits for 56 days. All women will receive live attenuated JE and Typhoid Vi-PS vaccine on study day 28. Vaccine response will be measured 28 days after vaccination (on day 56) in both groups.
We hypothesize that a high CD4+ and CD8+ T cell count will reduce viremia upon challenge with a structurally heterologous virus, and correspondingly result in reduced magnitude of host response to challenge infection. Primary Objective: To compare, after challenge with a structurally heterologous vaccine, the differences in levels of viremia between healthy adults who received primary vaccination with either YF17D vaccine, chimeric JE-YF17D vaccine, or inactivated JE vaccine. 58 subjects will be randomised into 1 of 2 arms (Arm B1 and Arm B2) in a 1:1 ratio, in a double-blind fashion. Subjects in Arm B1 will receive JE-YF17D vaccine (Imojev, Sanofi Pasteur) on Day 0 followed by YF17D vaccine (Stamaril, Sanofi Pasteur) on Day 28. Subjects in Arm B2 will receive Stamaril on Day 0 followed by Imojev on Day 28. Arm B3 will be conducted as a separate single-arm open label design in 14 subjects. Subjects in Arm B3 will receive inactivated JE vaccine (Ixiaro, Valneva) on Day 0 followed by Stamaril on Day 28. The rationale for these three study arms is as follows: Arm B1 will show the impact low levels of viremia, and the resultant low levels of virus-specific CD4+ and CD8+ T cells, would have on YF17D infection. In contrast, YF17D vaccination in Arm B2 would produce high levels of viremia, and in turn high levels virus-specific T cells, thus likely ameliorating JE-YF17D infection. Arm B3 will serve as the control arm, as vaccination with inactivated JE vaccine would not produce any YF17D-specific T cell response. Notably, the first vaccination in Arms B1 and B2 would also provide the viremia response in the absence of virus-specific T cells, which would serve as a reference point to interpret the outcome of the second vaccination.
This study is to evaluate the seroprevalence of neutralizing antibodies against Japanese encephalitis (JE) virus in children aged 6 years who were previously administered with 5 different immunization strategies by JE attenuated live vaccine (JEV-L) or/and inactivated vaccine (JEV-I). The secondary objective is to evaluate the immunogenicity of the booster dose of JEV-I at 6 years old for those previously immunized with 3 doses of JEV-I or those sequential administered with 1 dose of JEV-L and another dose of JEV-I.
This study evaluates the immunogenicity and safety of a purified inactivated JE vaccine compared to a commercialized JE vaccine. In this phase III, randomized, blind trial, infants at 6-23 months of age were randomly assigned to three groups to receive experimental vaccine or control vaccine with two different vaccination schedule respectively.
The aim of this study is to investigate the immune responses following a booster immunisation with the Japanese Encephalitis vaccine in elderly subjects (above 60 years of age) in comparison to a young study group.
There is a pressing need for a better experimental system to understand flavivirus antibody responses, beyond dengue, to make sure the investigators are using current vaccines to greatest effect and to inform the development of next-generation vaccines. This study will use live chimeric JE vaccine IMOJEV® as a tool for flavivirus epitope discovery. This will allow experimental JEV infection using replication competent, live, attenuated virus as a model, in a setting where the flavivirus infection history of humans can be tightly controlled.
A study of the study vaccine (JECEVAX- VABIOTECH-Vietnam) and a licensed vaccine (JEVAX-VABIOTECH-Vietnam) is conducted in Vietnamese children, aged 9 to 24 months to assess the safety of the study vaccine compares to licenced vaccine. Two hundred and twenty children are enrolled and randomly assigned into 2 groups (110 children/group), each of which receive 2 doses of study / control vaccine subcutaneously, at 28-34 days interval. Safety data included immediate reaction at the injection site and systemic reaction within 30 min of administration, solicited and unsolicited adverse events occurs from the 1st dose to 28-34 days after first dose and from the second dose to 28-34 days after 2nd dose. SAE (from start of first dose to 28-34 days after second dose).
A study of the study vaccine (JECEVAX- VABIOTECH-Vietnam) and a licensed vaccine (JEVAX-VABIOTECH-Vietnam) is conducted in Vietnamese children, aged 9 to 24 months to assess the safety of the study vaccine compares to licenced vaccine. Two hundred and twenty children are enrolled and randomly assigned into 2 groups (110 children/group), each of which receive 2 doses of study / control vaccine subcutaneously, at 28-34 days interval. Safety data included immediate reaction at the injection site and systemic reaction within 30 min of administration, solicited and unsolicited adverse events occurs from the 1st dose to 28-34 days after first dose and from the second dose to 28-34 days after 2nd dose. SAE (from start of first dose to 28-34 days after second dose).