Next alarm signal

Only one mutation separates bird flu from humans

Concerns about the widespread spread of bird flu among humans in Europe have been a recurring theme in recent years - but now the scenario is actually becoming more concrete in the USA.

(Bild: APA/AFP/CARL DE SOUZA)

Scientists are sounding the alarm: according to a recent study, the H5N1 virus, better known as bird flu, only needs a single mutation to bind more efficiently to human cells. Is the world really on the brink of a new pandemic?

The H5N1 avian influenza virus, which currently occurs mainly in US dairy cows apart from birds, may be on the verge of becoming a major threat to humans, according to a new study.

In a study for the renowned journal "Science", scientists have discovered that just one genetic mutation could be enough for it to bind more easily to human cells. This could create the conditions for transmission between humans - a potential scenario for a global pandemic.

Due to possible health consequences, the consumption of raw milk is currently strongly discouraged in the USA.

(Bild: AP ( via APA) Austria Presse Agentur/AP)

"Scary how quickly the virus could adapt"
"It's scary how quickly the virus could adapt," explains James Paulson, one of the study authors and a biochemist at the Scripps Research Institute. In the experiment, the researchers found that a single mutation in the surface protein of the virus, called hemagglutinin, was sufficient for it to dock better to human cells instead of bird bodies.

Although there is no evidence of human-to-human transmission so far, the danger remains real. Particularly critical: the virus already affects various animal species such as wild birds, bears, foxes and marine mammals - and has recently also reached dairy cows. This widespread spread increases the probability that the decisive mutation step will occur in nature.

Avian flu with pandemic potential
In previous years, the H5N1 virus was primarily known for severe respiratory diseases, as it prefers to attack cells in the lower lungs. However, the mutation tested in the current study could enable the virus to infect the upper respiratory tract. "Although this would make the symptoms milder, it would increase the likelihood of transmission through coughing and sneezing," warns immunologist Jenna Guthmiller.

Particularly alarming: a recently reported case in Canada showed similar mutations in the virus of a teenager who was hospitalized in critical condition. Even though scientists emphasize that further investigations are necessary, many experts see this case as a warning signal.

"The magic we don't want to see"
However, the researchers emphasize that bonding alone does not cause disease. For a pandemic to occur, several factors would have to come together, such as the ability of the virus to multiply in the human body. "The magic we don't want to see is that all the factors come together and the virus makes the decisive leap," says Paulson.

Given the potential danger, experts are calling for strict monitoring of mutations and precautions to prevent uncontrolled spread. "It's never good news when a virus is just one mutation away from infecting people more efficiently," summarizes Guthmiller.