Comparison of pathogenicities of H7 avian influenza viruses via intranasal and conjunctival inoculation in cynomolgus macaques

- Pathogenicity of H7 influenza viruses in monkeys was examined.
- H7 viruses were inoculated in noses and eyes of monkeys to mimic natural infection.
- H7N9 influenza virus isolated from humans replicated airways and eyes of monkeys.
- Not all H7 highly pathogenic avian influenza viruses cause symptoms in monkeys.

The outbreak of H7N9 low pathogenic avian influenza viruses in China has attracted attention to H7 influenza virus infection in humans. Since we have shown that the pathogenicity of H1N1 and H5N1 influenza viruses in macaques was almost the same as that in humans, we compared the pathogenicities of H7 avian influenza viruses in cynomolgus macaques via intranasal and conjunctival inoculation, which mimics natural infection in humans. H7N9 virus, as well as H7N7 highly pathogenic avian influenza virus, showed more efficient replication and higher pathogenicity in macaques than did H7N1 and H7N3 highly pathogenic avian influenza viruses. These results are different from pathogenicity in chickens as reported previously. Therefore, our results obtained in macaques help to estimate the pathogenicity of H7 avian influenza viruses in humans.