In February 2025, flu charges spiked to the highest ranges seen in at the least 15 years, with flu outpacing COVID-19 infections and hospitalizations for the primary time because the starting of the COVID-19 pandemic. The Facilities for Illness Management and Prevention has categorized this flu season as having “excessive” severity throughout the U.S.
The Dialog requested epidemiologist Annette Regan to clarify why this flu season is totally different from final 12 months’s and what folks can do to assist scale back the unfold.
How do flu instances and hospitalizations this 12 months examine with earlier years?
Starting in late January and lengthening by way of February 2025, flu hospitalizations have been larger than some other week since earlier than 2009.
Most flu instances look like from influenza A strains, with a break up between influenza A/H3N2 and influenza A/H1N1. These are two totally different subtypes of the influenza A virus.
Researchers consider that traditionally seasons which can be predominated by influenza A/H3N2 infections are typically extra extreme, however infections from influenza A/H1N1 can nonetheless be very extreme.
This 12 months’s season can be peaking “late” in contrast with the previous three flu seasons, which peaked in early or late December.
Sadly, there have been quite a lot of deaths from flu too this season. Since Jan. 1, 2025, alone, over 4,000 folks, together with 68 youngsters, have died from flu. Whereas the variety of deaths don’t mark a file quantity, it exhibits that flu is usually a critical sickness, even in youngsters.
allowfullscreen=”allowfullscreen” frameborder=”0″>
Why are flu instances so excessive this 12 months?
There are a variety of things behind any extreme season, together with poor group safety from low immunization charges and low pure immunity, virus traits, vaccine effectiveness and elevated human contact by way of journey, workplace work or faculties.
Sadly, flu vaccination charges have declined because the COVID-19 pandemic. On the finish of the 2023-24 flu season, 9.2 million fewer doses had been administered in pharmacies and docs’ places of work in contrast with a mean 12 months earlier than the pandemic.
As well as, since 2022, fewer and fewer doses of flu vaccine have been distributed by non-public producers. Flu vaccination charges for adults have traditionally been within the 30% to 60% vary, a lot decrease than the advisable 70%. Earlier than the COVID-19 pandemic, flu vaccination charges had been growing by round 1% to 2% yearly.
Flu vaccination charges started dropping after the COVID-19 pandemic, particularly in higher-risk teams. Flu vaccination in youngsters has dropped from 59% in 2019-20 to 46% in 2024-25. In adults 65 years and older, the group with the best danger of hospitalization and loss of life, flu vaccination charges dropped from 52% in 2019-20 to 43% in 2024-25.
Decrease vaccination charges imply a better portion of the inhabitants will not be protected by vaccines. Knowledge exhibits that vaccination reduces the chance of flu hospitalization. Even when a vaccinated individual will get contaminated, they might be much less prone to expertise extreme sickness. In consequence, low vaccination charges might contribute to larger flu severity this season.
Nevertheless, low vaccination charges are in all probability not the one purpose for the excessive charges of flu this season. In earlier extreme seasons, genetic adjustments to the viruses have made them higher at infecting folks and extra prone to trigger extreme sickness.
The effectiveness of annual flu vaccines varies relying on how effectively the vaccine matches the circulating virus. The effectiveness of vaccines ranges from 19% to 60% in any given season. Within the 2023-24 flu season, the vaccine was 42% efficient.
Equally, early 2024-25 knowledge from the U.S. exhibits that the vaccine was 41% to 55% efficient in opposition to flu hospitalizations in adults and 63% to 78% efficient in opposition to flu hospitalizations in youngsters.
allowfullscreen=”allowfullscreen” frameborder=”0″>
How do seasonal flu signs differ from COVID-19 and different diseases?
It is vital to keep in mind that folks usually incorrectly confer with “the flu” after they have a standard chilly. Flu is precipitated solely by the influenza virus, which tends to be extra extreme than widespread colds and extra generally causes a fever.
Lots of the indicators and signs for flu, COVID-19 and different respiratory viruses are the identical and may vary from gentle coldlike signs to pneumonia and respiratory misery. Widespread flu signs are fever, cough and fatigue, and may embrace shortness of breath, a sore throat, nasal congestion, muscle aches and headache.
Some signs, equivalent to adjustments in or lack of style and odor, are extra widespread for COVID-19. For each COVID-19 and flu, the signs don’t begin till about one to 4 days after an infection, and signs appear to last more for COVID-19.
The one approach to know what virus is inflicting an an infection is to check. This may be finished utilizing a fast take a look at, a few of which now take a look at for flu and COVID-19 collectively, or by seeing a physician and getting examined utilizing a nasal swab. There are prescription antiviral drugs accessible to deal with flu and COVID-19, however they have to be taken close to the time that signs begin.
Some individuals are at excessive danger of extreme flu and COVID-19, equivalent to those that are immunosuppressed, have diabetes or have continual coronary heart or lung situations. In these instances, it is very important search early care and remedy from a well being care skilled. Some docs may even prescribe by way of telehealth calls, which will help scale back the pressure on docs’ places of work, pressing care facilities and emergency rooms when an infection charges are excessive.
What can folks do now to assist avoid the flu?
There are a variety of the way folks can scale back their danger of getting or spreading flu. Because the flu season remains to be underway, it is not too late to get a flu vaccine. Even in seasons when the vaccine’s effectiveness is low, it’s prone to supply higher safety in contrast with remaining unvaccinated.
Handwashing and disinfecting high-traffic surfaces will help scale back contact with the flu virus. Taking efforts to keep away from contact with sick folks can even assist, together with sporting a masks when in well being care services.
Lastly, keep in mind to handle your self. Exercising, maintaining a healthy diet and getting ample sleep all assist assist a wholesome immune system, which will help scale back probabilities of an infection.
Those that have been identified with flu or are experiencing flu-like signs ought to keep away from contact with different folks, particularly in crowded areas. Protecting coughs and sneezes will help scale back the quantity of virus that’s unfold.
Annette Regan, Adjunct Affiliate Professor of Epidemiology, College of California, Los Angeles
This text is republished from The Dialog below a Artistic Commons license. Learn the authentic article.
