Late-stage testing of the vaccine is set to begin in 2025. This article reports that the CDC contends that bird flu, or avian influenza, is a virus that primarily infects birds but can sometimes infect other animals and, recently, has been reported to occasionally infect farm workers in contact with infected chickens or cattle.

The virus has been claimed to have spread to 129 dairy herds in 12 states in the country and infected various mammals, including alpacas and house cats, and there are fears that the virus may be getting closer to widespread human-to-human transmission. Critics against the COVID virus and vaccines are wary.