The rise in influenza cases has prompted a new warning from the World Health Organization. Credit: Hryshchyshen Serhii, Shutterstock
Although there is no immediate need for alarm as a new strain of influenza is raging around the world, the World Health Organization urges governments, doctors and citizens to remain vigilant.
In a new update, the WHO warned that global surveillance systems are picking up on clear changes in the influenza virus. Experts say this change has what experts call “pandemic potential.” That doesn’t mean a pandemic is imminent, but it does mean the virus is evolving in a way that deserves your close attention.
Flu season arrives early and lasts longer
Seasonal influenza is something that medical institutions predict every year. What is unusual this time is how uneven the current wave is.
In several countries in the Northern Hemisphere, influenza activity has begun earlier than expected, with case numbers rising faster than the typical winter peak. Other countries are also seeing steady increases, and while they have not yet reached epidemic levels, they are still above normal at this point in the season.
Meanwhile, the flu season in parts of the Southern Hemisphere is extending far beyond normal years, experts say, another sign that this year’s pattern is not going as planned.
WHO says overall activity is still within what is considered the normal seasonal range. However, some regions are also seeing “early increases and higher-than-normal activity,” so health authorities are paying closer attention than usual.
tension causes concern
At the heart of the WHO’s warning is the increasing predominance of influenza A(H3N2) viruses. Since August 2025, one particular subgroup known as the J.2.4.1 or K subclade has been rapidly spreading around the world.
It’s not the spike in severity that’s gotten scientists’ attention. So far, there is no evidence that people infected with this strain are becoming more seriously ill than usual. Rather, what stands out is the genetics of the virus.
WHO says these viruses exhibit several mutations that are different from other circulating A(H3N2) strains, indicating notable evolutionary changes. In layman’s terms, the influenza virus is adapting, and every time it happens on a large scale, the question arises: what will happen next?
This is where the term “potential pandemic” comes into play. This reflects a need for vigilance rather than panic. Medical experts stress that identifying these changes early is exactly how to manage and contain future risks.
Do current vaccines still protect us?
There is encouraging news in that regard. Early estimates suggest that existing influenza vaccines still have their place in preventing severe illness and hospitalization in both adults and children.
What is not yet clear is how effective they will be at preventing the mild forms of influenza associated with this evolving strain. Still, the WHO clearly states in its advice that vaccination remains one of the most effective tools available, especially for older people, people with underlying health conditions, and front-line health workers.
Behind the scenes, the virus is being tracked through the WHO’s Global Influenza Surveillance and Response System, a vast network of more than 160 laboratories and institutions in 131 countries. It serves as an early warning system for the world against new influenza viruses that may pose a broader threat.
To stay ahead of developments, WHO has ramped up extensive preparedness planning. This includes continued global monitoring, updating vaccine recommendations, strengthening laboratory capacity, tracking antiviral resistance, and improving communication as the influenza season progresses.
Health authorities say no drastic measures are needed for now. But the message is clear. Influenza should never be underestimated.
As winter weather continues to get harsher in many parts of the world, the WHO says it will continue to closely monitor developments and update guidance if the situation changes. The virus may still be behaving like the seasonal flu, but the way it’s changing is enough for experts to keep a close eye on it.
