Highly pathogenic avian influenza A H5N1 and pandemic H1N1 virus infections have different phenotypes in Toll-like receptor 3 knockout mice.

Toll-like receptors (TLRs) play an important role in innate immunity to virus infections. We investigated the role of TLR3 in the pathogenesis of H5N1 and pandemic H1N1 (pH1N1) influenza virus infections in mice. Wild-type mice and those defective in TLR3 were infected with influenza A/HK/486/97 (H5N1) or A/HK/415742/09 (pH1N1) virus.

Experimental challenge of chicken vaccinated with commercially available H5 vaccines reveals loss of protection to some highly pathogenic avian influenza H5N1 strains circulating in Hong Kong/China.

Highly pathogenic avian influenza (HPAI) H5N1 virus continues to circulate in poultry in Asia and Africa posing a threat to both public and animal health. Vaccination, used as an adjunct to improved bio-security and stamping-out policies, contributed to protecting poultry in Hong Kong from HPAI H5N1 infection in 2004-2008 although the virus was repeatedly detected in dead wild birds. The detection of clade 2.