Open AccessInvestigation of immune response induction by Japanese encephalitis live‐attenuated and chimeric vaccines in mice
Author(s) -
Fang Enyue,
Liu Xinyu,
Liu Xiaohui,
Li Ming,
Wang Ling,
Li Miao,
Zhang Zelun,
Li Yuhua,
Yu Yongxin
Publication year - 2022
Publication title -
medcomm
Language(s) - English
Resource type - Journals
ISSN - 2688-2663
DOI - 10.1002/mco2.117
Subject(s) - japanese encephalitis , virology , japanese encephalitis vaccine , immune system , elispot , neutralizing antibody , dengue vaccine , attenuated vaccine , immunization , biology , antigen , heterologous , yellow fever vaccine , immunology , virus , flavivirus , yellow fever , t cell , encephalitis , dengue virus , gene , virulence , biochemistry
The Japanese encephalitis (JE) live‐attenuated vaccine SA14‐14‐2 and the chimeric vaccine IMOJEV (JE‐CV) are two kinds of vaccines available for use worldwide. JE‐CV was previously known as ChimeriVax‐JE, that consists of yellow fever vaccine 17D (YFV‐17D) from which the structural genes (prM/E) have been replaced with those of SA14‐14‐2. This study aimed to investigate the neutralizing antibody, protection efficacy, and specific T‐cell response elicited by both vaccines in mice. The neutralizing antibodies produced by JE‐CV were slightly lower than those produced by SA14‐14‐2, but the protection conferred by JE‐CV was considerably lower in the low vaccine dose immunization group. Furthermore, the JE‐CV did not induce a specific T‐cell response against JEV NS3, while it did induce a potent antigen‐specific T‐cell response against the viral backbone vaccine YFV. In conclusion, this study is the first detailed investigation of the cellular immune response to the two vaccines. Enzyme‐linked immunospot (ELISPOT) and flow staining suggest a more potent specific T‐cell response against the JEV antigen was elicited in mice immunized with SA14‐14‐2 but not JE‐CV. Using heterologous flaviviruses as a live‐attenuated vaccine backbone may unlikely generate an optimal T‐cell response against the vaccine strain virus and might affect the protective efficacy.