Flu viruses usually cause the most illness during the colder months of the year. In the United States, flu season is from October to May. Most cases happen from late December to early March. It's best to get the flu vaccine early in flu season, ideally by the end of October. That way, the body has time to make antibodies that protect it from the flu. What if you aren't vaccinated by then? Getting the vaccine later is better than not getting it at all. It's still flu season well into spring. Even then it's not too late for you and your family to get the flu vaccine. Many health care providers give flu vaccines through May if the flu virus is still circulating. Getting a missed flu vaccine late in the season is especially important for people who travel. That's because the flu can be active around the globe from April to September. The flu season seemed milder during the COVID-19 pandemic, as fewer people got infected or were hospitalized with the flu. Experts are studying why that might be. It could be tied to public health measures that protect against coronavirus, as they also protect against the flu. These include wearing masks in public, social distancing, and lack of travel. Increased flu vaccination rates also might have helped. COVID-19 is getting lots of attention now, but many people get very sick or even die from the flu every year. So it's still important to get a flu vaccine each year. Back to Articles Related Articles First Aid: The Flu Telltale signs of the flu include a sore throat, body aches and fever. Here's what to do if your child has the flu. Read More Flu Center Get the basics on how flu spreads and how to protect yourself. Read More Flu Center The flu can make you sick for a week or more. Find out how to get protected from the influenza virus. Read More Flu Center Learn all about protecting your family from the flu and what to do if your child gets flu-like symptoms. Read More 5 Ways to Fight the Flu Get tips for fending off the flu in this article for teens. Read More 5 Tips for Surviving Shots If you're afraid of shots, you're not alone. Next time your doc asks you to roll up your sleeve, try these tips. Read More Flu The flu is a virus that can make you sick for a week or longer. Find out more in this article for kids. Read More Who Needs a Flu Shot? Just about everybody needs a flu shot. Find out more in this article for kids. Read More Your Child's Immunizations: Influenza Vaccine (Flu Shot) Find out when and why kids need to get the flu vaccine. Read More Tips for Treating the Flu Here are some quick tips for helping your child get over the flu. Read More Is It a Cold, the Flu, or COVID-19? Your child has a sore throat, cough, and a high fever. Is it COVID-19? Could it be the flu? Or just a cold? Here are tips on what to look for, and what to do. Read More Who Should Get the Flu Vaccine? The flu vaccine is a good idea for all families. It does not cause the flu, and it helps keep kids and parents from getting sick. Read More The Flu Vaccine Doctors recommend that all teens get vaccinated against the flu. Here are the facts on flu vaccines. Read More The Flu (Influenza) Flu symptoms tend to come on quickly and are worse than the sneezing and stuffiness of a cold. The flu is very contagious. Find out what to do in this article for parents. Read More Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.