Robert Redfield made this statement in an interview with the American TV channel NewsNation
Wild birds carry numerous influenza viruses, including some that could cause a pandemic if they are transmitted to people. The former director of the Centers for Disease Control and Prevention (CDC) told a US cable news channel that a bird flu pandemic is «very likely.»
Virologist Robert Redfield, who served as CDC director from 2018 to 2021, noted that avian influenza in humans is associated with «significant mortality» and that the death rate from this pandemic could far exceed what scientists have seen with COVID-19.
Many influenza viruses affect wild bird populations around the world, but most do not pose a serious threat to humans. Problems arise when a strain of bird flu mutates and becomes capable of being transmitted to a different host species. All four major influenza pandemics that affected humanity in the 20th and 21st centuries, including the 1918 Spanish flu and the 2009 swine flu, are believed to have begun due to the avian influenza virus.
“Recently they have become more severe fears that another pandemic strain may be upon us, thanks to the almost unprecedented spread of highly pathogenic H5N1 influenza among wild and domestic birds and, most importantly, many different species of mammals,” experts comment.
Outbreaks among cattle on dairy farms in several US states have already resulted in the virus spreading to farm cats and three workers who had mild illness. Viral particles have also been found in beef and milk, although experts continue to stress that the food is safe and the risk of illness in this way for the general population is small.
“I do think it is very likely that in some The moment we have an avian flu pandemic, it's not a matter of if, but rather when,” Redfield told host Chris Cuomo during an interview.
He added that the U.S. has seen a steady increase in the number of infected mammals since 2019, with some of the latest new cases bringing the total to about 27 different species.
H5 avian influenza subtypes, including H5N1, have long raised concerns about a future human pandemic. The recent case of human infection and death due to the H5N2 virus in Mexico has highlighted the danger that any of these diseases can pose to mammals, although the world's attention remains focused on the H5N1 virus as it has spread to even the most remote regions.
“As H5N1 infects different mammals, it learns to use different receptors in dolphins, seals, bears, foxes, raccoons and cats,” Redfield explained. “So it goes through a lot of changes, and as it acquires some of these new receptors, it can get closer and closer to humans.”
Surveillance remains key, and health authorities around the world are closely monitoring the spread of this virus. As Redfield noted, there is no easy way to predict how long it might take a virus to develop the necessary mutations that could lead to a pandemic.
It is emphasized that there is currently no evidence that the virus has evolved the ability to be transmitted from humans to a person. The small number of human infections so far have been isolated cases associated with very close contact with infected animals. But even this was enough for Finland. It will be the first country to begin immunizing people at risk.
“The existing supply of vaccines is a big plus, and that's what we didn't have in the fight against COVID as the pandemic intensified in 2020. We hope that other lessons humanity has learned from SARS-CoV-2 will serve us well when the next pandemic arrives,” concludes the former director of the US Centers for Disease Control and Prevention.