Intranasal immunization with coxsackievirus A16 virus-like particles confers protection against lethal infection in neonatal mice

Arch Virol. 2019 Dec;164(12):2975-2984. doi: 10.1007/s00705-019-04418-3. Epub 2019 Sep 30.

Abstract

Coxsackievirus A16 (CV-A16) is one of the main causative agents of hand, foot and mouth disease (HFMD) in young children and has become prevalent in the Asia-Pacific region in recent years. However, no approved vaccines or drugs are available for CV-A16 infection. CV-A16 virus-like particles (VLPs) are a potential vaccine candidate; however, whether the intranasal route of immunization is suitable for inducing immune responses against CV-A16 infection has not been clarified. In this study, the comprehensive immunogenicity and protective efficacy of the CV-A16 VLP vaccine were evaluated by multiple methods in a mouse model. In mice, a high neutralizing antibody (NTAb) titre could be elicited by intranasal immunization with CV-A16 VLPs, which produced NTAb levels similar to those induced by intranasal immunization with inactivated CV-A16. Passive immunity with NTAbs provided very good protection, as the survival rate of the immunized neonatal mice was 100% after challenges with CV-A16 at a dose of 1000 LD50. Passive protective effects were transferred to the neonates via the mother, thus protecting all the pups against challenges with the homologous or heterologous strains of CV-A16 at a dose of 1000 LD50. In addition, intranasal immunization with CV-A16 VLPs also induced the production of mucosal secretory IgA (s-IgA) antibodies, which may inhibit CV-A16 virus invasion. This study provides valuable supplemental information to facilitate our understanding of the specific protective efficacy of CV-A16 VLPs and has significance for development of the candidate vaccine into a safe and effective vaccine.

MeSH terms

  • Animals
  • Animals, Newborn
  • Antibodies, Neutralizing / immunology
  • Antibodies, Viral / immunology
  • Disease Models, Animal
  • Enterovirus A, Human / genetics
  • Enterovirus A, Human / immunology*
  • Enterovirus Infections / immunology
  • Enterovirus Infections / prevention & control*
  • Enterovirus Infections / virology
  • Female
  • Humans
  • Immunization
  • Mice
  • Mice, Inbred ICR
  • Nose / virology*
  • Viral Vaccines / administration & dosage*
  • Viral Vaccines / genetics
  • Viral Vaccines / immunology

Substances

  • Antibodies, Neutralizing
  • Antibodies, Viral
  • Viral Vaccines