Key points from article :
The H5N1 bird flu virus, which has already spread widely among birds and occasionally infects humans, may be closer to becoming airborne and posing a pandemic risk than previously thought. Recent studies reveal that the 2022 variant of the virus binds more effectively to human nose and throat cells compared to earlier strains. This change could enable it to infect cells lining the upper respiratory tract, a key step for airborne transmission through coughing or sneezing. A single mutation in the virus’s haemagglutinin protein could make this possible, though other genetic changes would still be needed for widespread human transmission.
Despite these findings, experts caution that the overall risk remains low, as multiple factors must align for the virus to cause a pandemic. However, every human infection increases the likelihood of additional mutations or gene-swapping with human flu viruses, a process known to have triggered past pandemics. This is particularly concerning given the virus’s expanding reach and the occasional severe disease it causes in humans.
If H5N1 were to achieve sustained human-to-human transmission, the severity of its impact remains uncertain. While half of confirmed cases since 2003 have been fatal, the true fatality rate could be lower, as mild cases often go undetected. Encouragingly, most recent infections in the U.S. have caused mild symptoms, possibly due to the mode of exposure. However, researchers stress that predicting how the virus might evolve and spread is complex, and the potential consequences warrant close monitoring.
