USDA conditionally approves H5N1 poultry vaccine

The US Department of Agriculture (USDA) has given a conditional approval to animal healthcare company Zoetis for an updated vaccine to protect poultry against the H5N1 bird flu strain. The Zoetis vaccine contains a killed version of an H5N2 variant that the company designed to work against currently circulating variants of the H5N1 virus.

The avian influenza has been spreading in dairy cow and poultry farms in the United States, causing at least several dozen infections in humans and one death. Although vaccination can help control the virus spread, the US government has long resisted its use, unlike those of China, Mexico, Egypt and France, where poultry are vaccinated against avian flu. So far, highly pathogenic influenza viruses have been eliminated from affected flocks by euthanasia. But this strategy has failed to eradicate the H5N1 viruses of the clade 2.3.4.4b that has been circulating in the country since February 2022.

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