The Surge in Flu Cases in the US is Triggered by 'Super Flu', Doctors Say the Symptoms are More Severe

JAKARTA - The United States is facing an unusual flu season. This year, the number of flu cases and hospitalization rates have increased sharply compared to the previous year.

As reported by the New York Post website on Saturday, December 27, 2025, the US Centers for Disease Control and Prevention (CDC) reported that there have been around 4.6 million flu cases nationwide.

This condition triggers concerns because the peak of the flu season usually lasts until at least February. This means that the surge in cases due to the flu variant dubbed 'super flu' is expected to not subside in the near future.

The variant in the spotlight is the subclade K, part of the influenza A virus of type H3N2. The H3N2 type often dominates the flu season, and this latest variant is responsible for more than half of the flu cases in the US until mid-November.

"This flu season is no joke. We are seeing more cases than usual at this time," Dr. Amanda Kravitz, a pediatrician at Weill Cornell Medicine, New York, told CBS Mornings.

Unlike the common flu, the H3N2 virus is known to cause more severe symptoms. The sufferers are reported to have high fever, extreme fatigue, severe muscle pain, sore throat, chills, runny nose or nasal congestion, to vomiting and diarrhea.

According to experts, there is one striking difference compared to the flu in previous years, namely the intensity of the symptoms that appear very quickly.

"The symptoms are very intense and come on really quickly. This virus is also very contagious, so it spreads quickly in the community," Kravitz added.

In addition to more severe symptoms, an increased risk of hospitalization is a major concern. If left untreated, this flu infection can develop into serious complications such as ear and sinus infections, bronchitis, pneumonia, and even death. The CDC notes that as of December 13, there have been about 1,900 deaths from flu.

One of the causes of the severity of this year's flu season is the decline in vaccination rates. The number of people who receive flu vaccines is reported to be less than in previous years. Even for those who have been vaccinated, the protection obtained is not as optimal as expected.

This happens because the flu vaccine is made 6-9 months in advance, based on predictions of virus mutations. Although usually quite accurate, this season the predictions are considered less accurate.

"The dominant strain this year is not very consistent with the vaccine, so there is a possibility that the proportion of people who are susceptible to flu will be larger," said Neil Maniar, Director of the Master of Public Health Program at Northeastern University.

In general, the effectiveness of the flu vaccine ranges from 40 to 60 percent. However, reports from the UK show that this year's vaccine effectiveness is only about 32-39 percent in adults, while in children it is still relatively high at 72-75 percent.

The spread of this 'super flu' is not only happening in the US. Flu cases are reported to have increased in the UK and Canada. Japan has declared a national influenza outbreak earlier than usual, with more than 6,000 cases recorded.

However, experts still emphasize that vaccination is the best available protection measure. In addition, the use of N95 masks in public places and limiting activities when sick is also recommended.

If infected, patients are advised to stay at home and follow treatment, including the use of antiviral drugs that can help reduce symptoms and shorten the illness.