Yes, You Need Both the Flu and COVID-19 Shots

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Key Takeaways

  • To be protected against both the flu and COVID-19, you must get both shots.
  • Some research indicates that the flu shot may offer a small amount of protection against some severe COVID-19 outcomes, though there is no evidence that it can create the anitbodies needed to mount a full immune response.
  • It is safe and effective to get both shots at the same time.

Though COVID-19 cases in the United States are falling, hospitalizations and deaths remain high. The approach of flu season means even more people are at risk of becoming seriously ill with a respiratory infection.

Public health officials are urging Americans to get both the flu and COVID-19 shots to protect themselves and others against the deadly viruses. But some Americans are confused about the difference between the flu and the COVID-19 symptoms and the shots.

In a Harris Poll survey of 2,000 American adults, 23% believe the flu shot would protect them against the coronavirus, and 26% think the COVID-19 vaccine would protect against the flu. A quarter of the participants think a COVID-19 booster shot will protect them from the flu.

“It's important for people to get a flu shot to protect against flu and a COVID vaccine to protect against COVID,” Edward Belongia, MD, director of the Center for Clinical Epidemiology and Population Health at the Marshfield Clinic, tells Verywell. “They’re very different viruses. We wouldn't expect the immune system to recognize, or to overlap in protecting us from both viruses.”

Can One Shot Protect Against Both Viruses?

The short answer is no. According to the Centers for Disease Control and Prevention (CDC), “flu vaccines do not protect against infection and illness caused by other viruses that also can cause flu-like symptoms.”

The COVID-19 and flu shots create specific antibodies and other protective immune cells that are uniquely equipped to protect against the viruses the vaccines were designed for.  

While it’s necessary to be vaccinated against both viruses to fully protect yourself, recent research shows there may be some benefit to being inoculated against influenza if you are infected with COVID-19.

At a recent National Foundation for Infectious Diseases panel, Cedric Jamie Rutland, MD, an emergency response doctor, said he has seen several cases of patients who tested positive for both COVID-19 and Influenza A when presented to the emergency room. In these patients, the ones who were vaccinated for COVID-19 did not have as severe inflammation as those who were unvaccinated against both diseases.

“I find it interesting because the inflammatory response—the immune system—is going to be activated,” Rutland said.

Some researchers hypothesize that there is a small amount of protection from the flu shot when an individual is infected with COVID-19, partially because it activates the cellular immune system.

In a retrospective paper from January, researchers found that COVID-19-positive children who were vaccinated against flu in the current flu season had a lower risk of developing symptomatic and severe illness from COVID-19. A similar study of adults 65 years and older found the influenza vaccine “may only marginally protect people from COVID-19 infection.”

A recent retrospective study of nearly 75,000 patients found that the annual flu shot reduced the risk of stroke, sepsis (an overactive and life-threatening response to an infection) and deep vein thrombosis in some patients with COVID-19.

These findings aren’t yet supported by clinical data, and Belongia emphasizes that there are likely many factors to consider when drawing meaning from these studies. For instance, people who tend to get their flu shots may also be more likely to take precautions against COVID-19. Plus, Belongia says that any protection from one vaccine against the other virus may be relatively weak and short-lived.

“There's still a lot that we don't fully understand about the immune response to both of these vaccines,” Belongia says. “There's going to be a lot more to learn in the coming years, but we understand how the major protection works in terms of the antibodies, and through that major mechanism of protection, there's no cross-reactivity.”

Now Is The Time to Get a Flu Shot

There are few cases of flu in the U.S. now, but experts say the future of this flu season is unpredictable.

The U.S. has seen a surge in respiratory syncytial virus and other cold-causing viruses this year, CDC Director Rochelle Walensky said in a recent panel on the flu season. The trend may be an indication that case rates for other respiratory viruses, like influenza, will have be higher this season than last, she said.

Plus, some places across the country are seeing weakened COVID-19 prevention measures, like mask mandates.

“We are worried that having not seen some of these respiratory viruses last year—because we were all sort of taking those prevention mitigation strategies—we may see more of them in the year ahead,” Walensky said.

“As the people who work in flu like to say, ‘if you've seen one flu season, you've seen one flu season.’ Each one is distinctive,” William Schaffner, MD, professor of medicine at Vanderbilt University and Medical Director of the National Foundation for Infectious Diseases, tells Verywell.

Health officials recommend getting your flu shot by the end of October. You can safely get both shots at the same time. This means that if you’re missing both vaccines, you can streamline your visits.

“It really is important for all to get vaccinated, not only for our own benefit, but it will take a strain off the healthcare system, because COVID will still be out there this fall and winter,” Schaffner says.

What This Means For You

The CDC recommends that everyone over the age of 6 months gets the flu shot, with a few exceptions. You can get a free flu shot through your doctor, pharmacies, walk-in clinics, grocery store clinics, and more. Flu activity typically peaks in December and it takes a few weeks for immunity to kick in, so experts recommend getting the shot by the end of October.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.

6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. COVID Data Tracker.

  2. Centers for Disease Control and Prevention. Influenza: How Well Flu Vaccines Work.

  3. Huang K, Lin SW, Sheng WH, et al. Influenza vaccination and the risk of COVID-19 infection and severe illness in older adults in the United States. Nature Scientific Reports. May 26, 2021. Doi: 10.1038/s41598-021-90068-y.

  4. Taghioff SM, Slavin BR, Holton T, et al. Examining the potential benefits of the influenza vaccine against SARS-CoV-2: A retrospective cohort analysis of 74,754 patients. PLOS One. August 3, 2021. DOI: 10.1371/journal.pone.0255541.

  5. Centers for Disease Control and Prevention. Weekly U.S. Influenza Surveillance Report (FluView).

  6. Centers for Disease Control and Prevention. The National Respiratory and Enteric Virus Surveillance System.

By Claire Bugos
Claire Bugos is a health and science reporter and writer and a 2020 National Association of Science Writers travel fellow.