Recent research has uncovered that the highly pathogenic H5N1 avian flu virus may pose a greater risk to humans when transmitted from cattle than from birds. A team led by Yoshihiro Kawaoka, director of the University of Tokyo’s Pandemic Preparedness, Infection, and Advanced Research Center, published these findings in the British scientific journal Nature on July 9.
Increased Infectivity from Bovine Sources
The research, reported by local media and cited by Xinhua news agency, involved testing human respiratory cell receptors with both bovine-derived and avian-derived H5N1 viruses. The results indicated that the bovine-derived virus exhibited stronger binding strength, suggesting a higher efficiency in infecting humans compared to its avian counterpart.
Pathogenicity in Mammals
The study further demonstrated the severe pathogenic effects of the bovine-derived virus in mammals. In experiments with mice and ferrets, the bovine-derived H5N1 virus not only multiplied throughout the body, including the brain and muscles, but also exhibited high virulence.
Implications for Human Health
Kawaoka emphasized the potential shift in the virus’s nature, raising concerns about future human-to-human transmission. Despite H5N1’s notorious infectivity and virulence in birds, global outbreaks in the 2000s primarily affected poultry. However, since 2020, various mammals have shown signs of infection, with 28 human cases reported to the World Health Organisation. So far, no human-to-human transmission has been confirmed.
Conclusion
This research underscores the evolving threat of the H5N1 virus, highlighting the need for heightened vigilance and preparedness in the face of potential new pathways of infection.
