Flu season is coming: What to know about new vaccine, when to get your shot and more

Doctors recommend most people over 6 months should get vaccinated.

By
Yi-Jin Yu
via
September 15, 2026, 4:21 PM ET
5 min read

Flu season is around the corner.

Here's what to know and how to prepare you and your family before the season's peak period kicks into high gear within the next three months.

Currently, the Centers for Disease Control and Prevention notes that seasonal flu activity is low across the U.S., but typically, flu season picks up by December and peaks during the winter months.

2026-2027 flu strains

Last season, the flu accounted for about 32 million illnesses and 24,000 deaths from 2025 to 2026, according to CDC data.

This year, scientists have recommended trivalent flu vaccines that cover these three strains that are expected to circulate:

  • Influenza A H1N1
  • Influenza A H3N2
  • Influenza B

    • When to get a flu vaccine

    ABC News Medical Correspondent Dr. Darien Sutton said experts recommend anyone 6 months old and over should get a flu shot in the fall, between September until the end of October.

    "They always say 'flu before boo,'" Sutton said in an interview that aired on "Good Morning America" Sunday. "The reason for that is to prime your immune system. As a reminder, it takes about two weeks to develop those protective antibodies and the peak of the flu season is around December to February."

    A new flu vaccine option for 2026

    This year, the FDA has approved a new mRNA flu vaccine option for adults 50 years and older, called mFLUSIVA, from drugmaker Moderna.

    "The mRNA vaccine gives your cells instructions to train your immune system," Sutton explained.

    FDA approves Moderna's mRNA seasonal flu vaccine

    Reported side effects of mFLUSIVA are similar to those of other vaccines, and may include mild reactions such as fatigue, muscle and joint aches, and injection site pain.

    Sutton said those who have experienced past reactions to certain flu vaccines should also consider other options that may be available to them, whether they are injectable or a nasal spray vaccine, which is approved for those between 2 and 49 years old.

    "If you've had a reaction or symptoms to a prior flu vaccine, check to see what type that was. There are many different options so you can reduce your chances of having a severe reaction if you did have one before," Sutton said.

    What you need to know about updated COVID vaccines following FDA approval

    Who shouldn't get a flu vaccine

    Although a flu vaccine is recommended for most, there are some individuals for which a flu vaccine may not be recommended.

    According to the CDC, these populations should avoid getting a flu vaccine:

  • Children under 6 months old
  • Anyone with a severe, life-threatening allergy to any of the ingredients in a flu vaccine. Examples may include but are not limited to: gelatin, antibiotics or other ingredients.
  • Anyone who has had a severe allergic reaction to a flu vaccine

    • Anyone with questions or considering a flu vaccine should consult with their doctor to identify the best option and appropriate vaccination for them.