Long-term efficacy of an inactivated H5N1 whole-particle influenza vaccine in cynomolgus macaques

Outbreaks of H5 highly pathogenic avian influenza A viruses (HPAIVs) in animals pose a threat to humans immunologically naïve to avian influenza viruses. To examine the long-term effectiveness of an H5 influenza virus vaccine, cynomolgus macaques were infected with an H5N1 HPAIV 5 years after two subcutaneous vaccinations with inactivated H5N1 whole-virus particles (H5 clade classical/outlier) and the gene expression in vaccinated macaques was compared with unvaccinated macaques after H5N1 HPAIV infection.