'Super flu' can extend flu season until February—expert

MANILA — The flu-like illness that has affected many Filipinos over the past several weeks may persist until February, according to infectious diseases specialist Dr. Rontgene Solante.

He says a possible factor behind the continued spread is the so-called “super flu,” or Subclade K of Influenza A. Symptoms of Subclade K, Solante explains, are largely similar to those caused by other influenza variants.

“In terms of the length of the symptoms, more or less they are the same,” Solante explained.

“That’s how influenza really is. Sometimes it can last more than 10 days, even up to two weeks, especially for those who are not resting, who continue to go out and work. You are always prone to relapse.”

Data from the World Health Organization show that Subclade K has been detected in more than 34 countries over the past six months, including the Philippines.

From January to October 2025, a total of 283 Influenza A cases in the country were genetically sequenced. Of these, more than 50 were identified as A(H3N2), with seven out of every ten A(H3N2) samples classified as Subclade K.

Compared to the earlier A(H3N2) strain, Subclade K carries nine mutations. While viral mutations are not unusual, Solante said these changes may influence how effectively vaccines work.

“Globally, many countries are now seeing more hospital admissions because of Subclade K. Some countries are also experiencing an earlier rise in influenza-like illnesses. This affects transmission, it becomes more contagious, and those who are unvaccinated are more likely to get infected.”

Despite these developments, studies show that existing flu vaccines remain effective. A recent study conducted in England found that influenza vaccines protect children from hospitalization at a rate of 72 to 75 percent, even against Subclade K. Protection for adults remains significant, though lower, at around 32 to 39 percent.

Health authorities continue to strongly advise vaccination against influenza, particularly for those planning to travel abroad.

Health Secretary Teodoro Herbosa, in a press conference on Wednesday, issued a specific warning for Filipinos traveling to temperate countries.

“The warning I will give is for Filipinos who will travel to temperate countries, who will go to North America and the UK,” Herbosa said.

“Be knowledgeable that there is a spread of super flu in that area. Get the northern hemisphere vaccine, not the southern hemisphere shot.”

Despite the continued circulation of Subclade K, experts stressed that there is no reason for fear or panic, as long as proper health precautions are observed.

These include wearing face masks when feeling unwell and in crowded or densely populated areas, as well as getting vaccinated and allowing adequate time for rest and recovery.

Source: www.abs-cbn.com