The US Department of Agriculture (USDA) has granted conditional approval for an updated bird flu vaccine designed to protect poultry against the H5N1 strain that has led to the loss of over 150 million birds across commercial and backyard flocks, Axios reports.
The current outbreak of H5N1 has devastated poultry populations, but existing vaccines do not fully match the dominant strain. As a result, officials are working to rebuild a national stockpile of vaccines for potential future use in livestock.
Additionally, while human infections remain rare, four US cases have been reported, with the most recent occurring in Ohio and Wyoming. Most human cases have been linked to direct exposure to infected animals rather than human-to-human transmission.
The USDA issued a conditional license to Zoetis, a global animal health company, for an updated version of a vaccine originally developed in 2001-02 during large bird flu outbreaks in Southeast Asia.
According to Zoetis, the license was granted based on demonstrated safety, purity, and a reasonable expectation of efficacy.
Following major avian flu outbreaks in 2014 and 2015, US officials created a national stockpile of vaccines for commercial poultry. However, these vaccines were never deployed.
While the USDA has no immediate plans to begin large-scale poultry vaccinations, the agency has stated it is moving forward with stockpile planning and securing vaccine manufacturing capacity as a precautionary measure.
In addition to poultry vaccines, the US government is preparing for the possibility of human infections. In January, the Biden administration awarded $590 million to Moderna to develop an mRNA vaccine for H5N1 that would specifically target the strains circulating in cows and birds.
