In the European Union, the European Commission’s Health Emergency Preparedness and Response Authority is working on a joint procurement of CSL Seqirus’s vaccine to "potentially prevent a pandemic" sparked by individuals exposed to infected birds and animals, spokesman Stefan De Keersmaecker said.A spokeswoman for CSL, which has contracts for pandemic influenza vaccines with 30 governments, said the company has been in talks with several governments about procuring vaccines since 2022.
The U.S. Food and Drug Administration approved a CSL influenza A vaccine in 2020, based largely on immunogenicity and safety results from a small clinical trial of 319 people.
Dr. Peter McCullough, an epidemiologist based in Texas, said on the social media platform X that without larger trials, it’s not possible to know whether the vaccine is safe or effective in humans.
The formulation for the CSL shot has been updated to more closely match the bird flu, which is an influenza A virus.
U.S. officials said recently that they’re planning to produce 4.8 million doses of the updated CSL vaccine. European health officials also said they were in talks to acquire CSL’s shot.
The decision on how and when to use the vaccine will hinge on evidence of increased transmission, severity of disease, cases in people with no link to a dairy farm, and mutations in the virus, U.S. Centers for Disease Control and Prevention (CDC) Principal Deputy Director Nirav Shah said.The agency says on its website that the government is developing bird flu vaccines "in case they are needed."
Human exposure to the virus in poultry and dairy operations could increase the risk that the virus will mutate and gain the ability to spread easily in people. Vaccines that perform poorly can also increase that risk.