Safety and Immunogenicity of a Single Administration of Live-attenuated Japanese Encephalitis Vaccine in Previously Primed 2- to 5-year-olds and Naive 12- to 24-month-olds

Abstract

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.

The yellow fever 17D virus as a platform for new live attenuated vaccines

“…Indeed, clinical trials have shown that YF17D-JE is safe and immunogenic with a single dose providing long-lasting immunity to wild-type strains of JE virus. [48][49][50][51] This recombinant technology-based vaccine was licensed for human use in Australia (Imojev-Sanofi-Pasteur). Accordingly, YF17D-WN chimeric viruses have also undergone clinical tests.…”

Immunogenicity and safety of currently available Japanese encephalitis vaccines: A systematic review

“…A Phase I RCT trial 27 including yellow fever (YF)-immune (n D 18) and non-YF-immune (n D 18) subjects showed the immunogenicity of a single dose of JE-CV at 2 different dosages (5.0 log 10 PFU vs. 4.0 log 10 PFU) was comparable to YF-VAX In a Phase II trial 28 with 99 adults in the USA, the immunogenicity of graded doses of JE-CV (1.8-5.8 log 10 PFU) was evaluated. 82 (94%) of 87 subjects administered JE-CV developed neutralizing antibodies.…”

Japanese encephalitis vaccines: Immunogenicity, protective efficacy, effectiveness, and impact on the burden of disease

“…Nakayama vs. Beijing-1 or SA14-14-2, or any of these vs. other wild-type G-III strains) with MBDI, SA14-14-2 LAV, JE-CV as well as Vero CCDI vaccines, although the differences in SCRs or GMTs are not significant statistically. 22,24,25,27,31,65,70,71,117,120,122,136,[165][166][167] This differential neutralization as well as protection against G-III viruses has also been shown in mouse challenge studies. 168 Other studies have shown no such differences or higher GMTs with the heterologous virus strains.…”

“…In general, these studies have shown that NAb titres are highest against G-II and homologous G-III viruses, followed by G-IV and heterologous G-III viruses, whereas titres against G-I viruses are the lowest, and in some cases below protective levels. 22,[24][25][26][27][28][29] A recent study specifically evaluated the ability of a G-III virus to elicit protective responses in mice, and the ability of human post-vaccinal and acute phase sera to neutralize G-V viruses. The study found that (a) NAb titres in mice immunized with either G-III or G-V virus were higher with homologous viruses but poor against G-V, (b) the SA14-14-2 LAV or the P-3 inactivated vaccines were less protective against G-V virus challenge in mice, and (c) both GMTs and SPRs were poor against G-V virus, intermediate against G-I virus, and highest against G-III virus with both post-vaccinal and acute phase human sera.…”

“…encephalitis, 21 (b) the fact that vaccination has significantly reduced JE cases (see below), and (c) studies of in vitro neutralization of heterologous genotype viruses by sera from subjects immunized with any one of the genotype viruses. 17,[22][23][24][25][26][27][28][29] Types G-I to G-IV have been frequently detected whereas G-V is relatively rare. 30 Viruses belonging to G-I have been reported from Australia, Cambodia, China, India, Japan, Malaysia, South Korea, northern parts of Thailand, and Vietnam; G-II has been reported from Australia, Indonesia, Malaysia (especially Sarawak), Papua New Guinea, South Korea, and southern parts of Thailand; G-III has been reported from China, India, Japan, Nepal, The Philippines, South Korea, Sri Lanka, and Taiwan; G-IV has been reported from Indonesia; G-V has been reported from China, Malaysia, and South Korea 31,32 It should be noted that in most endemic countries, more than one genotype may circulate simultaneously, with possible periodic changes in dominant genotypes.…”