Protective Efficacy of the H5 Inactivated Vaccine Against Different Highly Pathogenic H5N1 Avian Influenza Viruses Isolated in China and Vietnam.

The article details a study which examined the efficacy of inactivated H5N1 avian influenza (AI) vaccine in protecting chickens against different highly pathogenic H5N1 avian influenza viruses isolated in China and Vietnam. The study included groups of three-week-old specific-pathogen-free chickens that were intramuscularly injected with one dose of the vaccine. It found that H5N1 A/goose/Guangdong/1/96 (GS/GD/06)-based vaccine offers sound protection against clade 1, 2.2 and 3.3.4 viruses but not A/chicken/Shanxi/2/06 (CK/SX/06) virus. Study authors concluded that the antigenic match between inactivated vaccine and circulating virus can determine the efficacy of a vaccine in preventing H5N1 influenza virus replication and transmission.