Bird flu mutating could cause pandemic 'worse than COVID-19': Expert
28 Nov 2025

The bird flu virus poses a potential risk of causing a pandemic worse than COVID-19 if it mutates to transmit between humans, an expert said.

"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 center, told Reuters.

The Institut Pasteur was among the first European laboratories to develop and share COVID-19 detection tests.

Bird flu's impact on food supply and economy
Economic disruption

The highly pathogenic avian influenza has resulted in the culling of hundreds of millions of birds. This has severely disrupted food supplies and pushed up prices.

But despite its widespread impact on animals, human infections remain rare.

Rameix-Welti noted that while people have antibodies against common H1 and H3 seasonal flu viruses, they have none against the H5 bird flu virus affecting birds and mammals.

This is similar to how humans had no immunity against COVID-19 when it first emerged.

Lack of immunity against bird flu in humans
Immunity gap

Rameix-Welti also highlighted a key difference between the two viruses: unlike COVID-19, which mostly affects vulnerable populations, flu viruses can kill healthy individuals too.

The first human case of H5N5 was reported in Washington this month.

The individual, who had underlying conditions, passed away last week.

According to the World Health Organization's most recent report on bird flu, approximately 1,000 outbreaks in humans occurred between 2003 and 2025, primarily in Egypt, Indonesia, and Vietnam, with 48% of the victims dying.

Risk of human pandemic developing remained low
Research contribution

That being said, the chance of a human pandemic developing remained minimal, according to Gregorio Torres, head of the World Organisation for Animal Health's Science Department.

"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," he said.

Rameix-Welti also said that after the COVID pandemic, the world was better prepared than it was before.