Open AccessComparative Analysis of the Immunogenicity and Protective Effects of Inactivated EV71 Vaccines in Mice
Author(s) -
Qunying Mao,
Chuan Dong,
Xiuling Li,
Qiang Gao,
Zengbing Guo,
Xin Yao,
Yiping Wang,
Fan Gao,
Feng-xiang Li,
Miao Xu,
Wenzhe Yin,
Qihan Li,
Xin Shen,
Zhenglun Liang,
Junzhi Wang
Publication year - 2012
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0046043
Subject(s) - immunogenicity , adjuvant , enterovirus 71 , inactivated vaccine , immunization , dose , neutralizing antibody , medicine , virology , titer , vaccination , antibody response , antibody , immunology , virus , pharmacology , enterovirus
Background Enterovirus 71 (EV71) is the major causative agent of hand, foot, and mouth disease (HFMD). Three inactivated EV71 whole-virus vaccines of different strains developed by different manufacturers in mainland China have recently entered clinical trials. Although several studies on these vaccines have been published, a study directly comparing the immunogenicity and protective effects among them has not been carried out, which makes evaluating their relative effectiveness difficult. Thus, properly comparing newly developed vaccines has become a priority, especially in China. Methods and Findings This comparative immunogenicity study was carried out on vaccine strains (both live and inactivated), final container products (FCPs) without adjuvant, and corresponding FCPs containing adjuvant (FCP-As) produced by three manufacturers. These vaccines were evaluated by neutralizing antibody (NAb) responses induced by the same or different dosages at one or multiple time points post-immunization. The protective efficacy of the three vaccines was also determined in one-day-old ICR mice born to immunized female mice. Survival rates were observed in these suckling mice after challenge with 20 LD 50 of EV71/048M3C2. Three FCP-As, in a dose of 200 U, generated nearly 100% NAb positivity rates and similar geometric mean titers (GMTs), especially at 14–21 days post-inoculation. However, the dynamic NAb responses were different among three vaccine strains or three FCPs. The FCP-As at the lowest dose used in clinical trials (162 U) showed good protective effects in suckling mice against lethal challenge (90–100% survival), while the ED 50 of NAb responses and protective effects varied among three FCP-As. Conclusions These studies establish a standard method for measuring the immunogenicity of EV71 vaccines in mice. The data generated from our mouse model study indicated a clear dose-response relationship, which is important for vaccine quality control and assessment, especially for predicting protective efficacy in humans when combined with future clinical trial results.