When the CDC released its latest round of recommendations regarding seasonal flu vaccines, the agency made one notable update: Flu vaccines and COVID-19 vaccines can now be given simultaneously.

The guidance is a marked change from previous agency recommendations, which said that other vaccinations should not be administered within a 2-week window before or after the COVID-19 vaccine.

“We believe flu vaccination is very important in the context of ongoing COVID-19 activity,” Lisa A. Grohskopf, MD, medical officer in the CDC’s Influenza Division, said in an interview.

COVID-19 is keeping the health care system extremely busy, she said. And while last year’s flu season was nearly non-existent, “we are seeing the return of other common respiratory viruses, so we anticipate that we will experience an annual epidemic of flu this season as we do during most winters.

“Substantial flu activity occurring at the same time as COVID-19 activity could overwhelm our health care systems,” she added.

Universal Recommendations Unchanged

The recommendations are intended to guide vaccine providers in the use of influenza vaccines for the upcoming flu season, from late fall through early spring. Not surprisingly, they recommend routine annual influenza vaccination for all people at least 6 months of age who do not have certain underlying conditions.

Following these precautions, the CDC’s Advisory Committee on Immunization Practices’ Influenza Working Group said, will not only reduce flu cases, but will also reduce symptoms that might be confused COVID-19. At the same time, preventing flu and reducing the severity of its symptoms will likely reduce doctors visits, hospitalizations, and intensive care unit admissions, which may then ease pressure on the health care system caused by COVID-19.

“ACIP and CDC’s universal flu vaccine recommendation has not changed,” Grohskopf said.

Everyone older than 6 months should get a flu vaccine every year, she said, with few exceptions. Some people at

For those at higher risk of developing severe flu complications, vaccination is especially important, including adults over 65, people with asthma, diabetes, heart disease and other chronic diseases, people who are pregnant, and children younger than 5, she said.

Several Updates

The recommendations have other important updates. First, the flu vaccines has been updated so they are designed to protect against four different flu viruses.

The agency also changed the recommended timing of flu vaccination for some groups of people, including pregnant people in the third trimester; non-pregnant adults, and children who need two doses (those age 6 months through 8 years who have never received a flu vaccine or who have not received a lifetime total of at least 2 doses).

Coadministration The Focus

Yet it was the new recommendation regarding simultaneous COVID-19 and flu vaccines that dominated the update. Although Grohskopf said there is little data surrounding the idea, experience with other vaccine combinations has show that both immune response and potential side effects are similar when given alone or with other vaccines.

“Based on this prior experience, we do not anticipate any unusual or unexpected safety problems with giving COVID-19 vaccines and flu vaccines at the same time,” she said.

And while Americans are now free to get both vaccines at the same time, Grohskopf was quick to point out that neither vaccine should be delayed.

“Ideally,” she said, “people should get their flu vaccines by the end of October. If COVID-19 booster shots are approved by FDA and recommended by ACIP, some Americans will not be eligible for their third dose of COVID-19 vaccine until later. People should go ahead and get their flu shot and then schedule their COVID-19 vaccine at the proper time.”

Andrew Noymer, PhD, did not see any problems with giving the COVID-19 and flu vaccines at the same time.

“The seasonal flu shot is very well tolerated, as is the COVID shot,” commented Noymer, of the Department of Population Health & Disease Prevention at the University of California, Irvine. He was not involved in preparing the CDC recommendations.

In an interview, Noymer said, “People often wonder, can the body ‘handle’ two vaccines simultaneously? The answer is yes, and we do this all the time. The MMR vaccine given to children is, in fact, a cocktail of three vaccines, and the MMRV is a cocktail of four. So I'm not concerned by dual administration of influenza and COVID vaccines.

“The reason for the recommendation of both at once is attrition: some people who intend to come back for their second shot wind up just skipping it. Thus, do them both at once.”