Health officials are urging preventative measures as a new subtype of teh H3N2 influenza virus, known as K, circulates globally and has been detected in three Argentinian provinces – Santa Cruz and Buenos Aires. While the current 2025 flu vaccine remains the primary defense against severe illness, experts are closely monitoring the variant’s behavior and adjusting vaccination strategies accordingly. This report details updated recommendations for vaccination, including expanded eligibility for young children and upcoming campaigns targeting RSV and measles, all aimed at protecting public health as we approach the holiday travel season.
Health officials are closely monitoring a new subtype of the H3N2 influenza virus, known as K, and emphasizing the importance of vaccination as a preventative measure. The update comes as global circulation of the virus increases, prompting concerns about potential spread and severity.
Vaccination Remains Key to Protection
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Public health experts are urging individuals in at-risk groups to ensure they are up-to-date on their vaccinations, particularly with the current 2025 flu shot. This recommendation is especially crucial for those planning travel to countries experiencing active H3N2 viral circulation.
Who Should Get Vaccinated?
The target population for vaccination includes children aged 6 to 24 months, pregnant individuals at any stage of pregnancy, and postpartum women who haven’t received a vaccine during gestation. Additionally, people aged 2 to 64 with underlying health conditions – such as diabetes, asthma, heart disease, kidney disease, compromised immune systems, obesity, or genetic/neuromuscular syndromes – are strongly encouraged to get vaccinated. Healthcare workers, individuals over 65, essential personnel, and travelers to areas with active viral spread are also prioritized.
Vaccines are currently available at over 800 vaccination centers throughout the province. A complete list of locations can be found here.
In response to the circulating H3N2 A/K variant, and following guidance from the Pan American Health Organization (PAHO) and the World Health Organization (WHO), officials are planning to expand vaccination eligibility to children aged 2 to 5 years. Plans are underway to secure additional vaccine doses if they are not already included in the national vaccination campaign scheduled to begin in March 2026.
Prevention and Prompt Medical Attention
The National Administration of Laboratories and Health Institutes (ANLIS) “Dr. Carlos G. Malbrán” has confirmed three cases of the K variant within the country: two in adolescents in Santa Cruz and one in a child in Buenos Aires. This confirmation underscores the need for vigilance and preventative measures.
Experts are reinforcing the importance of preventative actions, including frequent handwashing, adequate ventilation of indoor spaces, covering coughs and sneezes with the elbow, and proper hand hygiene after using disposable tissues. These simple steps can significantly reduce the risk of transmission.
Individuals experiencing respiratory symptoms – such as fever, cough, nasal congestion, conjunctivitis, sore throat, headache, muscle aches, difficulty breathing, or confusion – are advised to seek medical attention promptly, rather than self-treating. This is particularly important for children, seniors, and those with pre-existing health conditions. Early diagnosis and treatment can help prevent complications.
Additional Recommendations from the Committee
With the holiday season and summer vacations approaching – periods characterized by increased travel – health officials recommend families review and update their vaccination schedules to ensure everyone is protected.
Following national guidelines, the booster dose of the Triple Viral vaccine (measles, rubella, and mumps) will be administered earlier, starting in January 2026, for children between 15 and 18 months of age.
Children born up to June 30, 2024, will complete the vaccination schedule with a second dose at age 5. Those born between July 1 and October 1, 2024, will receive their second dose between 15 and 18 months and will not require a vaccine at age 5.
In 2025, 36 cases of measles were reported in the country, highlighting the continued importance of verifying and completing the measles vaccination schedule.
Respiratory Syncytial Virus (RSV) Vaccination Campaign
A vaccination campaign against Respiratory Syncytial Virus (RSV) will begin on January 12 of next year, targeting pregnant individuals between 32 and 36 weeks of gestation. This initiative is part of broader strategies to prevent respiratory illnesses and significantly reduce hospitalizations of newborns due to these infections.
