New H3N2 flu strain hits the US: why the elderly are vulnerable.

According to ТСН: The US is experiencing a new wave of flu caused by the mutated H3N2 strain. The most vulnerable to this infection are the elderly.

Flu in the US

Flu cases in the United States are rising due to a new strain of the virus, which is predominantly severe for older people. Doctors note that the increase in cases is linked to this new variant of flu, against which, according to experts, already available vaccines may be less effective.

However, experts reassure: although the epidemic season has yet to peak, the current surge remains within normal limits, and vaccinations likely still help reduce the risk of severe complications.

The Centers for Disease Control and Prevention (CDC) reports a significant increase in hospitalizations, emergency room visits, outpatient visits, and deaths related to the flu. It is expected that the peak of the epidemic season will occur in early February.

"The growth seems quite rapid, but it is not unusual. We often see that flu seasons develop quickly and intensively," explained epidemiologist and director of the Pandemic Center at Brown University School of Public Health Jennifer Nuzzo.

Experts predict further increases in cases following a sharp rise in recent weeks. Whether this season will be as challenging as the previous one remains to be seen. According to the CDC, last year there were 288 reported deaths of children from the flu — the highest number since the H1N1 swine flu pandemic in 2009-2010.

According to specialists, severe flu seasons typically alternate, likely due to maintained immunity after the previous year.

As of the beginning of the current flu season, which started at the end of September and may continue until March or even April, at least 4.6 million cases of illness have already been registered, with no fewer than 49,000 hospitalizations and about 1,900 deaths.

New H3N2 flu strain

This season is marked by a new strain of the virus. Changes in the virus are constant, necessitating annual updates to vaccine compositions. The new variant belongs to the H3N2 strain (Type A flu), which, according to the CDC, has quickly become dominant in the US.

This virus is associated with early and particularly severe flu outbreaks in Japan, Canada, and the UK. However, CDC epidemiologist Alicia Budd notes that despite the active circulation of the strain in the US, the overall level of illness remains within expected values.

"We are not seeing such a sharp early spike that some other countries have observed," Budd noted.

Who is most at risk from the H3N2 strain and are vaccines effective against it?

The H3N2 strain is traditionally associated with increased rates of hospitalization and mortality among the elderly. This new variant emerged in the summer, after American vaccine manufacturers had approved the formulation of vaccines for this season. This raises concern that vaccine effectiveness may be lower, which in turn could lead to an increase in severe cases and further strain on a healthcare system already battling other winter viruses.

Studies in the UK show that local vaccines are effective against the new strain, although their composition differs from American ones.

According to the CDC, around 40% of the adult US population has received the flu vaccine, while among children, this figure is even lower.

Nuzzo emphasized that vaccinations remain extremely important, despite the virus mutations.

"The flu vaccine may not fully prevent infection, but it definitely reduces the risk of hospitalization and can alleviate the course of the illness or shorten its duration," she said.

Flu in children and vaccinations

In Jacksonville, Florida, pediatrician Pamela Lindor from Bluebird Kids Health has already noted an increase in flu cases among children. During school hours, children suddenly develop high fever, headache, severe fatigue, and cough. If the illness is diagnosed within the first two days, the doctor prescribes antiviral treatment.

Federal officials have doubts about current vaccination recommendations for children, noting that too many vaccines are administered to children in the US compared to other countries. In early December, Trump initiated a review of vaccination schedules, particularly questioning the necessity of annual flu vaccinations for children.

Lindor stressed that for many years she has faced parents' reluctance to have their children vaccinated against the flu annually, even though they generally support other mandatory vaccines.

"This is somewhat disheartening, as we see many cases of flu during this time of year that could have been significantly reduced if people were more willing to get vaccinated," the doctor noted.

It should be noted that a new aggressive flu subtype — the 'variant K' — is actively spreading in the US, representing a critical threat to children and the elderly due to the risk of severe dehydration, respiratory failure, and prolonged fever.