Leading infectious disease experts warn that avian influenza could evolve into a human pandemic potentially more severe than COVID-19. The alert comes as the virus continues spreading among wild birds, poultry, and mammals worldwide.
Marie-Anne Rameix-Welti, medical director at Institut Pasteur’s respiratory infections centre, explained the primary concern. “What we fear is the virus adapting to mammals, and particularly to humans, becoming capable of human-to-human transmission,” she told Reuters.
Unlike COVID-19, which primarily affected vulnerable populations, influenza viruses can cause severe illness in healthy individuals, including children. This factor could make a bird flu pandemic particularly dangerous.
According to the World Health Organization’s latest report, nearly 1,000 human bird flu outbreaks occurred between 2003 and 2025. The case fatality rate reached 48%, significantly higher than COVID-19’s mortality rate.
Bird flu virus could risk pandemic worse than COVID if it mutates, France's Institut Pasteur says https://t.co/8lfQ7TMZJl https://t.co/8lfQ7TMZJl
— Reuters (@Reuters) November 27, 2025Most human infections resulted from close contact with infected animals. Recent cases include H5N1 infections in the United States and the first-ever human H5N5 case, which proved fatal.
A key concern is humanity’s lack of antibodies against H5 bird flu strains. Unlike seasonal H1 and H3 flu varieties, people have no natural immunity to avian influenza viruses.
However, experts note important advantages in pandemic preparedness. “We have vaccine candidates ready and know how to manufacture a vaccine quickly,” Rameix-Welti said. Global health agencies also maintain stocks of effective antivirals.
The World Organisation for Animal Health emphasizes that while vigilance is crucial, the current pandemic risk remains low. People can continue normal activities while health organizations monitor the situation closely.
