Flu: Symptoms, Spread, Treatment and Other Care Approaches

Sick Man With the Flu

Influenza — May 2026

See the US INFLUENZA MAP HERE - From January

6th, CDC - Map reflects data from July 2026

If you are looking for information about the current flu, strains, vaccines, tests and symptoms, read the following. Looking for conventional treatment and alternative complementary/supportive options for the flu? Click here.

Subclade K Flu: What You Need to Know

The current flu, is sometimes called the "Superflu" - not because it is more dangerous than others but because it easily spreads easily. Like most years, flu is still out there but is slowing down. The current strain is H3N2 strain, Subclade K, a mutation of H3N2 (it is not uncommon for a flu strain to mutate). It is an Omicron strain which tend to be accompanied by less severe than the original strains back in 2020 (but can still cause severe illness in some people). It now accounts for about 90% of U.S. flu cases.

Will a flu shot prevent the subclade K? While this year’s flu shot only offers modest protection against Subclade K, it still sharply reduces the risk of severe illness.

Will My Fu Shot Still Protect Me in May?

Full effectiveness of the flu shot begins to gradually wear off about five months after getting the flu shot. It will still provide some partial protection.

How Well This Year's Flu Shot Works

This year, because it mutated and started hitting people after the formulation of the vaccine - it mismatched - it was too late to change. However, it does help generate some antibodies, so it partially works: it can reduce hospitalizations, severe illness, and death. This is why it is still important to get the vaccine if you can tolerate it. This is particularly important for those with underlying medical problems and for older people.

If you don't get a flu shot this year, at least avoid sick people (especially in crowds) and wash your hands well and often.

Why did the vaccine miss the mark this year? Every spring, based on global flu activity, the WHO, CDC, and FDA review circulating strains and decide which ones should be included in the upcoming season’s vaccine. Normally, this is followed by an advisory committee meeting to finalize the formulation. That did not occur in the usual way this year. Instead, a closed‑door meeting was held with members of the FDA, CDC, and the Department of Defense. Once the FDA selects the strains, manufacturers begin production months in advance.

Because Subclade K emerged after this process was completed, the vaccine does not match the strain now causing about 90% of U.S. cases. Early estimates suggest the shot is 39–50% effective overall — modest for infection prevention, but still meaningful for reducing severe outcomes.

Do rapid flu tests detect the Subclade K variant? 

Because it is an H3N2 virus, the rapid tests do work, but, as with any strain, the tests are only about 50% sensitive in detection (in kids, they are about 50-80%).

Does the flu medicine, Tamiflu, work against Subclade K 

Yes, if taken early in the illness.

Does prior immunity to other flu strains help prevent Subclade K?

No

Symptoms of Subclade K Influenza:

What are we seeing with the most recent flu strain, Subclade K:

• High fever, sometimes for 5-7 days

• Body aches and joint pain

• Intense, lingering cough

• Fatigue and chills

• Sore throat and congestion

• Occasionally present with nausea, vomiting, and/or diarrhea

  Some people are getting pretty sick with this, including vital young people. The worst cases I am seeing are those with post-flu symptoms that are lingering. Instead of improving after 5-7 days, their symptoms are worsening, particularly chest congestion. If this happens to you, consider seeing a medical provider.

• Approaches to flu symptoms: Feel like you have the flu? Check out the following for some pointers: Conventional and Alternative Approaches to the Flu. 

  Understanding the Flu: Symptoms, Spread, Treatment, and Care Approaches

  
  

• Read about other contagious diseases: Where are we now? For the latest news about the flu, COVID-19, bird flu, Chagas, Legionella, Chikungunya, West Nile, Monkeypox