U.S. Prepares Bird Flu Vaccines as Precaution Against Potential Human Spread

The United States government is preparing two possible bird flu vaccines as a precautionary measure against the potential spread of the H5N1 virus from infected cattle to humans. Hundreds of thousands of vaccine doses are ready to be shipped within weeks if needed, despite no current evidence of person-to-person transmission.

The H5N1 bird flu virus has recently spread to dairy cows for the first time in the U.S., raising concerns about it potentially infecting humans through the nation's milk supply. Since 2022, the virus has infected over 90 million chickens, more than 9,000 wild birds, and 34 dairy herds, with two human cases reported so far.

Why this matters: The spread of bird flu to an increasing number of species and its widening geographic reach have raised the risks of humans being infected. Experts warn that the probability of the virus turning into a human virus is increasing as it continues to circulate in more mammalian species.

The U.S. government has confirmed bird flu infections in dairy herds across six states, including Ohio, Kansas, and New Mexico. The initial cases in Texas and Kansas appear to have been introduced by wild birds, with subsequent cases involving a very similar strain of the virus.

In response to the outbreak, the U.S. is testing four potential bird flu vaccines for poultry. Some of the world's leading flu vaccine makers say they could produce hundreds of millions of bird flu shots for humans within months if the virus jumps across the species divide.

The government has two bird flu vaccine candidates ready in limited quantities that could be widely distributed within weeks if needed. Hundreds of thousands of prefilled syringes and vials are prepared for shipment. The U.S. is also pursuing a third vaccine based on mRNA technology and testing blood samples to determine if existing influenza vaccines could provide some cross-protection.

Public health officials are urging increased vigilance and preparedness, expanding surveillance and testing efforts to better understand the spread and transmission of the virus, particularly among dairy and cattle farms. The government is also stockpiling vaccines and antivirals in case the virus becomes transmissible between people.

Key Takeaways

• U.S. preparing 2 bird flu vaccines as precaution against H5N1 virus spread.
• H5N1 virus has infected over 90M chickens, 9K wild birds, and 34 dairy herds.
• Experts warn of increasing probability of virus turning into human virus.
• U.S. testing 4 potential bird flu vaccines for poultry, stockpiling human vaccines.
• Outbreak is the nation's worst since 2015, leading to culling of 47M+ birds.