The U.S. Department of Agriculture (USDA) has granted Zoetis a conditional license for its Avian Influenza Vaccine, H5N2 Subtype, Killed Virus, intended for use in chickens.
According to Reuters, this approval is based on demonstrated safety, purity, and a reasonable expectation of efficacy supported by serology data.
A conditional license is issued to address emergency conditions, limited markets, or special circumstances and is valid for a finite period, subject to renewal at the USDA’s discretion.
National regulatory authorities, in collaboration with the poultry industry, make the decision to vaccinate commercial poultry flocks against Highly Pathogenic Avian Influenza (HPAI).
Zoetis has a history of developing avian influenza vaccines; in 2016, the company received a conditional license for its H5N1 vaccine, which was later used to protect California condors in 2023.
Additionally, Zoetis holds a USDA license for POULVAC® FLUFEND™ i AI H5N3 RG, utilized in 2024 to safeguard endangered birds in New Zealand.
Since February 2022, HPAI has affected over 150 million birds in the U.S., impacting both backyard and commercial flocks.
The Centers for Disease Control and Prevention (CDC) considers the risk to the general public to be low, as most human infections have occurred among farm workers exposed to infected animals.
However, experts caution that the virus could mutate, potentially increasing the risk of human-to-human transmission.
In response to the outbreak, the USDA is updating its stockpile of avian influenza vaccines to match the circulating virus strains.
Other companies, including Merck and Ceva, along with U.S. government researchers, are also developing vaccines to combat the spread of avian influenza.
The conditional approval of Zoetis’ vaccine represents a significant step in addressing the ongoing avian influenza crisis, providing poultry producers with an additional tool to protect their flocks and mitigate the impact of future outbreaks.
