Whole virion inactivated Enterovirus 71 vaccine – Immunogenicity and efciency in Balb/c mice

Abstract

This study was subjected to evaluate the immunogenicity and protective ability in mice of vero cell-based whole virion inactivated Hand Foot and Mouth Disease vaccine against enterovirus 71 (EV71) developed from the high pathogenic strain circulated in Vietnam EV71/B5.. Balb/c mice between 6 - 8 weeks old were assigned to 7 groups at different antigen dose 2.5µg, 5µg and 10µg with or without aluminum hydroxide, control groups with PBS and intramuscular immunized with two injections at 4-week intervals. Neutralizing antibody titer in groups receiving antigen formulated with aluminum hydroxide was higher compared to groups receiving antigen alone. The immune response was elicited in all the immunized groups and peaked after the booster. There was no significant difference in neutralizing antibody titer between 5µg and 10µg antigen dose. The challenge experiment was performed in 1-day-old neonatal mice whose mothers had previously been immunized with two injections at different antigen dose 2.5µg, 5µg and 10µg. The results revealed the protective effect of 70%, 90% and 100%, respectively. The vaccine has been shown the immunogenicity and protective efficacy in Balb/c mice.