Title: Efficacy of inactivated influenza vaccines for protection of poultry against the H7N9 low pathogenic avian influenza virus isolated in China during 2013 Authors
Submitted to: American Association of Avian Pathologists
Publication Type: Abstract Only
Publication Acceptance Date: February 1, 2014
Publication Date: N/A
Technical Abstract: The recent outbreak in China of avian influenza (AI) H7N9 in birds and humans underscores the interspecies movement of these viruses. Interestingly, the genetic composition of these H7N9 viruses appears to be solely of avian origin and of low pathogenicity in birds. Although few isolations of these viruses have been demonstrated on poultry farms, the correlation between live bird market shut downs and reduced human infections in China underscores a linkage between poultry and humans. We performed vaccine efficacy trials to determine the extent of protective efficacy with different inactivated H7 vaccines. Both homologous H7N9 and heterologous H7 isolates were tested as vaccines and injected at a dose of 512 HA units per bird. Birds were challenged 3 weeks post-vaccination with 10^8 EID50 per bird delivered via intranasal route. Results demonstrated 100 % protection with homologous antigen and minimal mortality with heterologous H7 vaccines. When birds received less than 512 HA units of homologous antigen 10 % mortality was observed. Taken together, these results indicate that the homologous vaccine can provide protection to poultry against this recent H7N9 virus.