Find out what you need to know on the 2021-2022 flu season

Disclaimer: At UPMC HealthBeat, we strive to provide the most up-to-date facts in our stories when we publish them. We also make updates to our content as information changes. However, education about COVID-19 can shift quickly based on new data, emerging variants, or other factors. The information in this story was accurate as of its publish date. We also encourage you to visit other reliable websites for updated information, including the Centers for Disease Control and Prevention (CDC), Food and Drug Administration (FDA), and your state and local governments. 

Updated November 2021

For the second straight year, the annual flu season is occurring during the COVID-19 pandemic.

With the highly contagious Delta variant (B.1.617.2) of SARS-CoV-2 spreading in the U.S., it’s as important as ever to take precautions against COVID-19 and the flu.

What Was the 2020-21 Flu Season Like?

Typical flu seasons in the United States from 2010 to 2020 averaged between 9 million and 45 million illnesses, according to the Centers for Disease Control and Prevention. Annual flu hospitalizations ranged from 140,000 to 810,000, and deaths ranged from 12,000 to 61,000. In a typical year, between 3% and 11% of Americans get sick from the flu.

Those numbers dropped dramatically during the 2020-21 flu season. The threat of a “twindemic” — a severe flu season combined with the COVID-19 pandemic — didn’t become reality:

Why were flu cases so low in 2020-21?

Several factors may have played a part in a milder 2020-21 flu season.

  • Vaccines: According to the CDC, a record 193.8 million Americans received flu shots during the 2020-21 flu season.
  • COVID-19 prevention methods: COVID-19 prevention efforts in the U.S. included facemask mandates, social distancing, increased hand hygiene, reduced travel, school and work closures, and more. Those same preventive tactics also may have helped limit the number of flu illnesses, hospitalization, and deaths.

It’s also possible that some people didn’t seek care for the flu during the 2020-21 flu season, even if they felt sick. However, higher vaccination numbers and other preventive efforts are likely the greater reason for the decline in cases.

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Will the 2021-22 Flu Season Be Bad?

A milder 2020-21 flu season does not guarantee the same will happen in 2021-22. Many schools are returning to full in-person learning this fall. Other COVID-19 preventive efforts, like masking and social distancing, have been relaxed.

Also, a low level of flu activity since the COVID-19 pandemic began could mean Americans have less flu immunity. That could lead to an earlier and more severe flu season, according to the CDC.

In August 2021, an analysis led by scientists from the University of Pittsburgh Graduate School of Health reported that the 2021-22 flu season is likely to be more severe than usual.

Do I Need a Flu Shot?

The best way to prevent the flu is by getting the flu shot. The effectiveness of the flu vaccine varies by year, but in most years, it is 40%-60% effective. The flu shot prevents millions of illnesses and thousands of hospitalizations and deaths each year, according to the CDC.

The CDC recommends all Americans 6 months old and above get a yearly flu shot. The best time to get the shot is September or October, but you can still get one later than that.

It is especially important for people at high risk of flu complications to get the shot. That includes:

  • Adults 65 and older.
  • Young children.
  • Pregnant women.
  • People with underlying health conditions, including asthma, diabetes, heart disease, or lung disease.

The 2021-22 flu vaccines are all “quadrivalent” vaccines, meaning they protect against four different flu viruses.

COVID-19 Vaccines and Flu Shots

In addition to the flu vaccine, the CDC recommends that all eligible Americans get the COVID-19 vaccine. Americans 5 and older are eligible for the COVID-19 vaccine.

The flu shot does not prevent COVID-19, and the COVID-19 vaccine does not prevent the flu. However, both vaccines are safe and effective — especially in preventing severe illnesses and death.

They significantly reduce your chances of having to fight off two significant illnesses at the same time.

You also can get your COVID-19 vaccine at the same time as your flu shot. Visit our COVID-19 vaccine page for information on how to schedule a COVID-19 vaccine appointment with UPMC.

How Can I Prevent the Flu?

In addition to getting the flu shot, you can take other actions to limit your risk of getting or spreading the flu:

  • Avoid people who are showing symptoms of the cold, flu, or COVID-19.
  • Stay home if you’re sick. Don’t expose others to illness by going to work or school while sick.
  • Cover your coughs and sneezes. Use a tissue, and throw the tissue away after using it.
  • Wash your hands frequently. Use soap and water, and scrub for at least 20 seconds before rinsing.
  • Avoid touching your eyes, nose, and mouth.
  • Frequently clean and sanitize commonly touched surfaces that may be contaminated with germs.

With the spread of the Delta variant in the U.S., some COVID-19 prevention measures also may help limit your risk from the flu.

  • Facemasks: Follow all local laws, restrictions, and guidelines regarding masking. If you are not fully vaccinated for COVID-19, the CDC recommends wearing a facemask in public. Even fully vaccinated people should wear masks in areas with high transmission rates of COVID-19. The CDC also recommends all students, teachers, and visitors to K-12 schools wear masks at all times while indoors.
  • Physical distancing: Avoid crowded public areas if you are not fully vaccinated against COVID-19.

For more information about the flu, visit For more information about UPMC’s efforts against COVID-19, visit

Centers for Disease Control and Prevention, 2020-21 Flu Season Summary. Link

Centers for Disease Control and Prevention, Disease Burden of Influenza. Link

Centers for Disease Control and Prevention, Frequently Asked Influenza (Flu) Questions: 2021-22 Season. Link

Centers for Disease Control and Prevention, Influenza, Preventive Steps. Link

Pennsylvania Department of Health, Department Of Health Provides Final Flu Update Of 2020-2021 Season; Highlights Include One Of Mildest Seasons On Record. Link

World Health Organization, Influenza Updates. Link

About UPMC

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