The bird flu virus that has swept through wild birds, poultry and several mammal species could fuel a pandemic worse than COVID-19 if it mutates to transmit efficiently between humans, the head of France’s Institut Pasteur respiratory infections centre has warned.
Marie-Anne Rameix-Welti, medical director at the renowned Paris-based institute, said the highly pathogenic H5 avian influenza virus poses a significant threat if it acquires the ability to spread from person to person. For now, human infections remain rare and typically linked to close contact with infected animals.
“What we fear is the virus adapting to mammals, and particularly to humans,” she told Reuters. “That virus would be a pandemic virus.”
The current strain of bird flu has already led to the culling of hundreds of millions of birds worldwide, disrupting food supplies and driving up prices. The Institut Pasteur was among the first European laboratories to develop and share COVID-19 detection tests during the 2020 pandemic, contributing critical support to global health systems.
No Natural Immunity to H5 Bird Flu
According to Rameix-Welti, one of the biggest concerns is that people have no antibodies against H5 bird flu strains—much like the lack of immunity seen at the onset of COVID-19.
Unlike COVID-19, which primarily affects older and vulnerable populations, flu viruses can cause severe illness even in healthy individuals, including children.
“A bird flu pandemic would probably be quite severe, potentially even more severe than the pandemic we experienced,” she said.
Nearly 1,000 human cases of H5 infections have been reported globally since 2003 — mostly in Egypt, Indonesia and Vietnam — with an alarming fatality rate of 48%, according to the World Health Organization. Recent cases include the first-ever human infection with H5N5 in Washington state this month; the patient, who had underlying conditions, later died.
Experts Say Pandemic Probability Still Low
Despite the warnings, global health authorities stress that the likelihood of a human-to-human transmission event remains low.
Gregorio Torres, head of science at the World Organization for Animal Health, said there is no reason for public alarm.
“We need to be prepared to respond early enough,” he said. “But for the time being, you can happily walk in the forest, eat chicken and eggs and enjoy your life. The pandemic risk is a possibility. But in terms of probability, it’s still very low.”
Better Prepared Than Before COVID-19
Rameix-Welti noted that if bird flu were to mutate into a transmissible human virus, the world is far more prepared than it was in 2020.
“The positive point with flu, compared to COVID, is we have specific preventative measures in place,” she said. “We have vaccine candidates ready and know how to manufacture a vaccine quickly.”
She added that stockpiles of antivirals—expected to work against current avian influenza strains—are already available.
