Federal agriculture researchers are developing a poultry-use vaccine against the highly pathogenic H5 influenza strains that have infected poultry and wildlife since December 2014.
Dr. David Suarez, research leader for the exotic and emerging avian viral disease unit at the Department of Agriculture’s Agricultural Research Service, said the ARS was performing safety studies on a vaccine that should be well-matched against all the highly pathogenic H5 influenza viruses discovered in the U.S. since December 2014, unlike available commercial vaccines that would not provide as much antigenic similarity. The vaccine still needed to be reviewed and approved under regulatory processes before it could be handled by outside companies, which would produce the vaccine if needed.
The H5 influenza viruses have been found in states ranging from Washington to Arkansas, spreading from detection only in the Pacific flyway through February to the Central and Mississippi flyways further east in March and April. That spread has been accompanied by discovery of the virus in increasing numbers of commercial poultry flocks, at least 13 reported so far.
USDA information indicates H5N2, H5N8, and H5N1 influenzas have been found, with one or more discovered as of April 22 in Arkansas, California, Idaho, Iowa, Kansas, Minnesota, Missouri, Montana, North Dakota, Oregon, South Dakota, Washington, Wisconsin, and Wyoming.
The H5N1 virus is a new combination of avian influenza genes and is not the same as the strains that have caused deaths in other countries, although it could cause disease in humans, according to information from the Centers for Disease Control and Prevention.
Dr. Suarez said U.S. poultry producers tend not to vaccinate flocks in the absence of a disease because the act of vaccination could imply to trading partners that the virus is present. Instead, such vaccines tend to be used to protect smaller portions of the poultry industry where the virus is or has been present, helping companies return to normal production.
CDC information indicates that no people were known to have become ill from exposure to the highly pathogenic H5 influenza virus strains. Similar viruses have caused human illnesses and deaths in other countries, but the public health risk from these influenza outbreaks is considered to be low.
“Most human infections with avian influenza viruses have occurred after close and prolonged contact with infected birds or the excretions/secretions of infected birds,” CDC information states.
Five poultry industry organizations published in March a joint statement intended to assure the public that private companies and government agencies were working to control the spread of the influenza viruses or eliminate them. The statement from the U.S. Poultry & Egg Association, National Chicken Council, National Turkey Federation, United Egg Producers, and USA Poultry and Egg Export Council indicates state and federal agencies have worked with the poultry industry to quarantine affected flocks, and birds from those flocks have been kept out of the food chain.