Bird flu virus could trigger pandemic worse than Covid — French expert

French health experts are warning that the bird flu virus that has been spreading among wild birds, poultry and mammals could set the stage for a pandemic worse than COVID-19 if the virus mutates to transmit between humans.

    Highly pathogenic avian influenza, commonly called bird flu, has led to the culling of hundreds of millions of birds in the past years, disrupting food supplies and driving up prices. A recent severe outbreak of bird flu has killed thousands of migratory cranes in eastern France since October 20th, prompting wildlife authorities to deploy emergency teams and farmers to cull infected flocks. Human infections remain rare.

    "What we fear is the virus adapting to mammals, and particularly to humans, becoming capable of human-to-human transmission, and that virus would be a pandemic virus," Marie-Anne Rameix-Welti, medical director at the Institut Pasteur's respiratory infections centre, told Reuters on Monday (November 24).

    The Institut Pasteur was among the first European labs to develop and share COVID-19 detection tests, making protocols available to the World Health Organization and labs worldwide.

    People have antibodies against common H1 and H3 seasonal flu, but none against the H5 bird flu affecting birds and mammals, like they had none against COVID-19, she said.

    And unlike COVID-19, which mainly affects vulnerable people, flu viruses can also kill healthy individuals, including children, she stressed.

    "A bird flu pandemic would probably be quite severe, potentially even more severe than the pandemic we experienced," she said in her Paris laboratory.

    The strain of bird flu that has caused the most damage among poultry and dairy cows in the U.S. is the H5N1. But a first ever human case of H5N5 appeared in Washington state this month. The man, who had underlying conditions, died last week.

    In its latest report on bird flu, the WHO said there had been nearly 1,000 outbreaks in humans between 2003 and 2025 - mainly in Egypt, Indonesia and Vietnam, of which 48% had died.

    "The positive point with flu, compared to COVID, is we have specific preventative measures in place. We have vaccine candidates ready and know how to manufacture a vaccine quickly," Rameix-Welti said.

    "We also have stocks of specific antivirals, that, in principle, would be effective against this avian influenza virus," she added.

Sybille de La Hamaide, Lucien Libert/Reuters