The immunogenicity and protection effect of the BPL-inactivated CA16 vaccine in different animal systems

We evaluated the effect of a β-propiolactone (BPL)-inactivated coxsackievirus A16 (CA16) vaccine, using three immunogenicity evaluation and two animal challenge systems. A CA16 virus strain, named 419, was used as the production strain. Another CA16 strain, named 1131, was isolated and used as the challenge strain in intracerebral inoculation of neonatal mice for the calculation of median lethal dose (LD 50). In the passive and maternal antibody-protection challenge systems, all results indicated that the vaccine could protect mouse pups from lethal challenge with the CA16 virus. In the immunogenicity systems, three types of animal (mouse, rat, and cynomolgus monkey), were immunized with the 419/CA16 vaccine. The dose-effect relationship and the antibody-generation routine were described. The CA16 vaccine induced a more potent serum antibody effect in rat than in mouse. The serum antibody titer was detectable more than 63 days after the initial vaccination. We also identified tools to evaluate the effect of the BPL-inactivated CA16 vaccine.