Influenza has been making headlines in the Northern Hemisphere. Rising rates of illness and hospitalization combined with growing attention to the newly emergent variant A(H3N2) subclade K have brought renewed focus to flu prevention.
The good news? Even now, with influenza activity high and a new dominant strain circulating, getting vaccinated still helps prevent severe illness, hospitalization, and death. In short: it’s not too late to get a flu shot.
Flu by the Numbers—Has the Season Peaked Yet?
It’s still too soon to know whether the 2025-2026 flu season in the Northern Hemisphere has peaked. Although infections and outpatient visits dipped slightly in the first few weeks of January, a second surge often follows the end-of-year holidays.
Despite any temporary decline, influenza activity remains high, with elevated rates of illness, hospitalization, and mortality compared with previous seasons. Several regions in the U.S. are also reporting strain on hospital capacity.
So far this season, the CDC estimates:
- 23 million illnesses
- 300,000 hospitalizations
- 19,000 deaths
This marks a notable increase from the same period last year. Use of DynaMed is also reflecting the magnitude of this situation, with a 40 percent increase in searches for Tamiflu dosing from the first to the second week of February.
Why Are Rates So High This Year?
A likely contributor is lower population immunity. Influenza A(H3N2) viruses have not been the dominant strain in recent flu seasons, leaving many people with less natural or vaccine-driven protection.
That said, available epidemiologic data, both in the U.S. and Europe, do not show increased disease severity. Early indications suggest that the 2025-2026 seasonal influenza vaccine continues to provide protection against severe illness, hospitalization, and death.
About Subclade K
Each year’s flu vaccine strains are selected months in advance based on global surveillance. Subclade K, also known as A(H3N2) subclade J.2.4.1, emerged after the 2025-2026 vaccine composition was finalized.
Laboratory testing shows that these viruses have drifted structurally compared with other recent strains. As a result, the vaccine doesn’t perfectly match the dominant flu virus variant for this season. While overall vaccine effectiveness for this season is still being evaluated, early estimates from the European Centre for Disease Prevention and Control suggest the vaccine may be about 50 percent effective against illness requiring medical care.
Even with this mismatch, vaccine protection against serious illness remains strong.
Good News on Antiviral Treatments
There is no evidence of antiviral resistance among A(H3N2) subclade K viruses. Nearly all circulating influenza viruses -- including all tested A(H3N2) subclade K isolates -- remain fully susceptible to influenza treatments including neuraminidase inhibitors such as oseltamivir (Tamiflu), and baloxavir, an endonuclease inhibitor.
Who Should be Vaccinated Against Influenza?
Everyone aged six months and older should receive an annual influenza vaccination unless they have a medical contraindication. This recommendation is especially important for people at higher risk of influenza-related complications, including:
- Persons ≥ 65 years old
- Children < 59 months old
- Individuals with chronic medical conditions (such as immunocompromise or pulmonary disease)
- Persons with body mass index (BMI) ≥ 40
- Pregnant persons
- Persons living in long-term care facilities or nursing homes
- Caregivers and household contacts of people at increased risk
Why Vaccinating Children Matters
Children play a central role in flu transmission within households, schools, and communities, often serving as the primary introducers of the virus into these settings. Annual vaccination reduces children’s risk of infection, hospitalization, and death.
As of February 7, 2026, there were 66 pediatric flu‑associated deaths reported in the United States. Among vaccine-eligible children with known vaccination status, 90 percent of these deaths occurred in those who were not fully vaccinated.
These data underscore the importance of timely and complete influenza vaccination to protect children and reduce community transmission. The American Academy of Pediatrics strongly recommends influenza vaccination for all children ages 6 months and older.
Flu Vaccination in the U.S.: Are We Reaching Everyone?
Despite clear evidence of benefit, only about half of people in the United States receive a flu vaccination each season.
Persistent racial and ethnic disparities are reflected in vaccination rates and influence outcomes:
- Estimated vaccination coverage (2023-2024) season:
- 50 percent among White, non-Hispanic persons
- 44 percent among Black, non-Hispanic persons
- 42 percent among Hispanic persons
- Hospitalization rates (2009-2022) compared with White adults:
- nearly 80 percent higher for Black, non-Hispanic adults
- about 20 percent higher for Hispanic adults
Barriers to vaccination include vaccine hesitancy fueled by misinformation and mistrust, limited access to care, and missed vaccination opportunities during routine healthcare visits.
Patient-centered approaches, including counseling, education, shared decision making, and other communication strategies can help improve vaccination uptake.
Bottom Line: It's Not Too Late to Vaccinate
The emergence of a new dominant strain and the high rate of influenza cases during this year’s flu season underscore the importance of influenza prevention. Even at this point in the season, getting vaccinated can greatly reduce the risk of severe illness, hospitalization, and death.
There is still time to protect your patients from influenza by improving vaccination rates in your community. It’s not too late to encourage your patients to get their flu shots. It’s not too late to vaccinate!
