The current season of flu in Europe it started three to six weeks earlier than in previous yearsaccording to the World Health Organization. In the UK, the National Health Service reported that daily flu hospital admissions rose from 1,717 to over 2,660 in just one week, with forecasts of up to 8,000 weekly hospital admissions. Spain, Germany, France and Italy have seen continued increases in casesand thus doubled its records compared to the previous year.
Subclade K is one of these newer variations of the H3N2 virus that is circulating in countries in the Northern Hemisphere and has attracted attention due to its widespread distribution. The Pan American Health Organization (PAHO) He specified that the genetic evolution observed in this subclade is part of the natural variation process of the seasonal influenza virus.
The K variant of H3N2identified by mutations in the hemagglutinin protein a 56% higher infection capacity to that of previous seasons, as he said in a note Infobae the Argentine doctor Martha Cohenbased in England. This mutation makes immune detection difficult, even in people who have already been vaccinated or already infected, which accelerated the spread in Europe and threatened hospital capacity.
Nevertheless, both the WHO and international experts agree on this No increase in individual severity of clinical cases was noted. The health impact lies in the large number of infections and the decline in the population’s immunity after years of low spread of the virus.
So far Argentina There have been no cases or spread of the K variant of the H3N2 virus. National authorities did not announce any specific recommendations in this regard, while in some provinces they stated that they were maintaining enhanced epidemiological surveillance, and in Córdoba it was reported that they would manage the early arrival of vaccines for the next season.
The K variant has already crossed continents. In MexicoThe National Institute of Respiratory Diseases confirmed the first discovered case of the new K variantHealed without complications and on an outpatient basis. At the end of epidemiological week 49 of 2025, 16.2% of confirmed influenza infections in Mexico corresponded to H3N2, with 154 cases registered. Health authorities stressed that the symptoms and clinical treatment are no different from those of seasonal flu, but stressed the need for it Get vaccinated, especially at risk groups.
Peru, for its part, decreed national epidemiological alert given the risk of entry and spread of the K variantin a context of high mobility and festivities. The Ministry of Health promoted active surveillance, timely diagnosis and vaccination, as well as measures such as frequent handwashing, wearing a mask when experiencing symptoms, and ventilating the environment.
Until now, Argentina reported no confirmed cases or spread of the K variant the H3N2 flu. And although the National Health Portfolio has not officially commented on the matter, the Ministry of Health of Córdoba and Argentine Respiratory Medicine Association (AAMR) formed an expert committee to anticipate scenarios given the possibility of a coincidence of outbreaks Dengue fever and respiratory diseases.
The Minister of Health of this province, Ricardo Pieckenstainer, explained this The voice that the committee has proposed increasing coverage against respiratory syncytial virus in pregnant women, promoting vaccination against Covid as soon as the new doses arrive for next year, and We need to manage the early rollout of flu vaccines for the 2026 season. In addition, the work plan, divided into six axes, includes a campaign consciousness The aim is to increase vaccinations and support the completion of vaccination plans. “He Expert advice will help you anticipate and implement effective plans” said the official.
From the Epidemiology Directorate of Mendoza, Andrea Flaschi confirmed: “There is currently no evidence of greater severity or increased risk for Argentina or Mendoza.” This was reported in Argentina in a statement from the Ministry of Health of this province No cases have been recorded The K subclass of influenza A(H3N2) is still circulating. Nevertheless, epidemiological surveillance is being strengthened and coordinated with national and international organizations, and the population is encouraged to comply with the vaccination schedule against influenza, COVID-19 and respiratory syncytial virus, especially in older adults, people with risk factors, pregnant women, young children and health workers, in addition to maintaining preventative measures such as frequent hand washing and room ventilation.
The main risk for Argentina lies in this Potential pressure on the health system if the variant invades and establishes immune gapsespecially in older adults, children, pregnant women, immunocompromised people and people with chronic illnesses. The ability of the H3N2 subtype to mutate rapidly could increase transmission and reduce immunological effectiveness.
According to AAMR and PAHO “A high vaccination rate” in risk groups is essentialas available data show that protection against hospitalization due to H3N2 remains adequate.
Experts such as Elena Obieta des Argentine Society of InfectologyThey warn about the importance of annual vaccination: “It doesn’t matter if you have five flu vaccinations: if the last one was in 2022, that’s not enough.”
Authorities remember the importance of Flu vaccination, against COVID-19 and respiratory syncytial virusthereby strengthening the protection of the most vulnerable. It is also recommended to maintain daily prevention habits: Constantly washing your hands, ventilating the area and using a mask if you have symptoms.
Faced with symptoms like fever, cough or feeling unwell, It is important to avoid work or school activities and seek medical attention. For whom Traveling to or returning from countries with active traffic For H3N2, it is important to follow vaccination schedules and watch for signs such as high fever, dry cough, sore throat, or difficulty breathing.
The active epidemiological surveillance and the timely vaccination will be crucial for Argentina to anticipate and mitigate the potential impact of the H3N2 influenza K variant outbreak. Experience in Europe and North America shows that even without major clinical severity, the combination of high risk of infection and lower immunity can test hospital capacity.
Early preparation and international cooperation are essential to reduce the burden of disease and protect the most vulnerable populations.
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