Comparing the immunogenicity and safety of 3 Japanese encephalitis vaccines in Asia-Pacific area: A systematic review and meta-analysis.

Japanese encephalitis virus (JEV), a leading cause of Japanese encephalitis (JE) in children and adults, is a major public health problem in Asian countries. This study reports a meta-analysis of the immunogenicity and safety of vaccines used to protect infants or children from JE. Three types of JE vaccine were examined, namely, Japanese encephalitis live-attenuated vaccine (JEV-L), Japanese encephalitis inactivated vaccine (Vero cell) (JEV-I(Vero)), and Japanese encephalitis inactivated vaccine (primary hamster kidney cell) (JEV-I(PHK)). These vaccines are used to induce fundamental immunity against JE; however, few studies have compared their immunogenicity and safety in infants and young children less than 2 years of age. Data were obtained by searching 5 databases: Web of Science, PubMed, China National Knowledge Infrastructure, the China Wanfang database, and the Cochrane database. Fifteen articles were identified and scored using the Jadad score for inclusion in the meta-analysis. Random effect models were used to calculate the pooled seroconversion rate and adverse reaction rate when tests for heterogeneity were significant. The results showed that the pooled seroconversion rate for JEV-I(PHK) (62.23%) was lower than that for JEV-I(Vero) (86.49%) and JEV-L (83.52%), and that the pooled adverse reaction rate for JEV-L (18.09%) was higher than that for JEV-I(PHK) (10.08%) and JEV-I(Vero) (12.49%). The pooled relative risk was then calculated to compare the seroconversion and adverse reaction rates. The results showed that JEV-I(Vero) and JEV-L were more suitable than JEV-I(PHK) for inducing fundamental immunity to JE in infants and children less than 2 years of age.

Meta-analysis on Serological Effect of the Primary Vaccination for Japanese Encephalitis of the Literatures / 中国疫苗和免疫

Objectives To summary and compare the different seroconversion rates after the primary vaccination for the Japanese encephalitis (JE),and to evaluate the serological effect of 3 kinds of JE vaccines.Method Searching "CHKD","Wanfang" database and "EMCC" databases,the studies of the immunogenicity after the primary JEV vaccination,all randomized controlled trials or non-randomized controlled trials were included,and statistical analysis were made by RevMan 4.2.10 software.Results A total of 12 literatures were included,7 studies had control groups.The seroconversion rates after the primary vaccination,JEV-L,JEV-I (Vero) and JEV-I(PHK),were 86% (95% CI:80% ～ 91%),83% (95% CI:72% ～ 94%) and 64% (95% CI:58% ～ 69%) respectively.Comparing the seroconversion rates of the 3 kinds of vaccines after primary immunization,the rate of JEV-I (Vero) was significantly higher than the rate of JEVI(PHK),other comparisons were no significant difference.Conclusion The serological effects of JEV-L and JEV-I (Vero) after the primary vaccination were higher than that of JEV-I (PHK).