Amid an outbreak of bird flu among U.S. poultry and dairy herds, the federal government on Friday announced $72 million in funding to three vaccine makers to expand production of bird flu vaccines for humans should they be needed.
The H5N1 virus has affected millions of wild and commercial birds across the country, and in March it first affected dairy cows. As the number of infected animals increases, the fear of transmitting the disease to humans increases. The H5N1 virus has historically had a high mortality rate in humans, so scientists are closely monitoring the virus to determine whether it poses a pandemic risk. The US government has a stockpile of approved H5N1 vaccines, but today’s awards to CSL Seqirus, GSK and Sanofi will double that number.
“We expect to have filled and used a total of just over 10 million doses by the end of the first quarter of calendar year 2025,” David Boucher, director of infectious disease preparedness and response for the Strategic Preparedness and Response Administration, said at a news conference on Friday.
Moderna, Pfizer and GSK are also working on mRNA vaccines for bird flu, but they must undergo human testing and be approved by the U.S. Food and Drug Administration before they can be used.
This year, 16 people in the US have been infected with bird flu. US Centers for Disease Control and Prevention confirmed the last two casesboth in California on Thursday night. These people are farm workers who came into contact with infected dairy cows at two facilities in the Central Valley, the epicenter of the state’s cattle outbreak. Both had gentle symptoms, including red eyes, and are being treated with antiviral drugs. None of them reported respiratory symptoms or were hospitalized.
Nirav Shah, the CDC’s principal deputy director, said the novel cases do not change the agency’s risk assessment for the general public, which remains low. “The discovery of these two cases was not unexpected,” he said during Friday’s briefing. “Because there are more flocks that test positive, more workers are at risk of infection, and the more workers are exposed, the risk of human infection increases.”
Both California cases are believed to be cases of animal-to-human spread of the virus, with no known link or contact between the two. California health officials are monitoring close contacts of workers, including household members who are also dairy workers.
The CDC says it will conduct additional testing of virus samples in the coming days, including genetic sequencing to monitor any changes in the virus. Scientists are particularly interested in whether the virus is developing novel mutations that could make it more likely to spread from person to person. The agency says there is currently no evidence that the virus can spread from person to person.
Of the 16 confirmed human cases, six were linked to exposure to ailing or infected dairy cows and nine were exposed to infected poultry. The source of infection has not been determined for the Missouri case.