Unlocking Immunity: How Childhood Flu Exposure Guards Against Bird Flu

Older adults with early influenza exposure may have antibodies that help fight bird flu, unlike younger individuals who may benefit more from vaccines. Researchers found that these antibodies can limit the severity of diseases like H5N1. This discovery may influence future vaccine strategies and public health policies.

Research suggests that older adults exposed to flu strains before 1968 might possess antibodies offering some protection against the H5N1 bird flu virus. This immunity could make vaccines more beneficial for younger individuals, according to a study published in Nature Medicine.

Scott Hensley of the University of Pennsylvania explains that childhood influenza exposure results in immunity that can last a lifetime. His research indicates that early antibodies, initially responding to H1N1 and H3N2 flu, could react to current H5N1 strains, though not preventing infection entirely, they might lessen disease severity in potential pandemics.

Researchers observed that, following a 2004 bird flu vaccine, antibody levels increased more in children than in older adults. Experts warn of the virus's mutation risks and advocate for broader vaccine distribution, particularly targeting younger populations. Meanwhile, with C.D.C. deeming current public risk low, this research might reshape future vaccine guidelines.

(With inputs from agencies.)