The flu season—which typically runs from October through May—can be severe. And for the past couple of years there has been the looming threat of a combination of a severe flu season with COVID-19 and respiratory syncytial virus (RSV). This year, while it was a busy summer with SARS-CoV-2 infections, the availability of an updated COVID-19 vaccine in addition to the influenza and RSV vaccines, offers hope for the winter season. But that is only if people use the tools to mitigate infection and illness. Everyone six months of age and older is recommended to get the influenza vaccine to reduce the risk of severe outcomes.
Last year’s flu season resulted in at least 35 million illnesses, 390,000 hospitalizations and 25,000 deaths in the U.S. This included 187 pediatric deaths, according to the Centers for Disease Control and Prevention (CDC). For the 2022–2023 flu season, the CDC estimated that flu vaccination prevented 6 million flu-related illnesses in the U.S., 2.9 million medical visits, 65,000 hospitalizations and 3,700 deaths.
The AMA’s What Doctors Wish Patients Knew™ series provides physicians with a platform to share what they want patients to understand about today’s health care headlines.
In this installment, Kate Kirley, MD—a family physician and director of chronic disease prevention at the AMA—took time to discuss what doctors wish patients knew about the influenza vaccine to help clear up any misinformation.
The vaccine doesn’t give you the flu
The flu vaccine is made of pieces of the virus or inactivated virus, and “the nasal spray is a whole virus, but it’s an attenuated form of the virus, so neither kind can actually give you the flu,” said Dr. Kirley. “It’s not uncommon for people to have a low-grade fever or feel a little run down for a couple of days after they get their vaccine. That’s just their immune system responding to the vaccine and doing exactly what we want it to do.”
Patients will sometimes coincidentally come down with the flu shortly after receiving the vaccination, but that’s just a quirk of timing, Dr. Kirley said, noting that this is one of many common misconceptions about influenza and flu vaccines.
“It takes the vaccine a couple of weeks to generate a full immune response, so you don’t have your full protection until a couple of weeks after you get your shot,” she noted.
OK for flu, COVID-19 shots at same time
The updated COVID-19 vaccine, designed to better match currently circulating variants, is now available for patients 6 months or older. Coadministration of flu and updated COVID-19 vaccines is recommended if you are eligible and the timing coincides.
“People heading to their doctor’s office or pharmacy for their COVID vaccine can also get their influenza vaccine at the same visit,” said Dr. Kirley. This means “people can get their flu shot on the same day—it’s safe and effective, so there’s no need to make multiple trips.”
“Every year, influenza causes hundreds of thousands of hospitalizations and tens of thousands of deaths in the United States,” she said, noting that “it’s important to do everything we can to keep people out of the hospital and getting a flu shot is one of the best things we can do to stay healthy during flu season.”
Additionally, it is “possible to get influenza and COVID at the same time, and then you really have that double whammy in terms of two significant respiratory illnesses,” said Dr. Kirley. The flu vaccine is “really to get the protection against that scenario.”
Getting a seasonal flu vaccine does not protect against H5N1 bird flu. But if a person may have frequent exposure to potentially infected birds or other animals, it is still important to get a seasonal flu vaccine two weeks before potential exposure. That is because it can reduce the prevalence and severity of seasonal flu and may reduce the very rare risk of coinfection with influenza and an avian virus at the same time, according to the CDC.
See what doctors want you to know
Get trusted insight from physicians on hot topics in today’s health care headlines—delivered to your inbox.
Can reduce flu risk by up to 60%
“We typically don't know the effectiveness of the vaccine until we really get into flu season, and we can see what types of viruses actually end up circulating in the population,” said Dr. Kirley, adding that every year, the flu vaccine is adjusted to align with what is predicted to be the most likely strains circulating.
“It typically falls somewhere between 40% and 60% effectiveness,” she said. “Even when the vaccine is only 30% effective at preventing flu, that is still very meaningful and crucial for preventing hospitalizations and deaths.”
Get it as soon as possible
The general recommendation is to “shoot for September or October to get your flu vaccine,” said Dr. Kirley. “You can start to get your vaccine, ideally before the end of October, but if you don’t squeeze it in, go get it any time.”
“Ideally before January is what’s best. But we’ll tell people all throughout flu season, if you haven’t gotten the vaccine yet, it’s still OK to get it and you’re likely to benefit as long as influenza viruses are circulating,” she said.
Everyone should get vaccinated
“There are a couple reasons why someone might not be able to get the flu vaccine—that’s relatively rare,” said Dr. Kirley. “A real allergy to it might be the most common reason, but generally speaking, if you are older than 6 months old, you should definitely get the flu vaccine.”
Older adults “are a higher-risk population. They have slightly different vaccine options that are designed to protect them a little bit more,” she said. “Because they are also clearly one of those high-risk populations for COVID, it is even more important for them to protect themselves against the flu as well.”
There are nasal sprays too
“The sprays are only approved for ages 2 through 49,” said Dr. Kirley. “There are some medical conditions or reasons why you may not be able to get the spray, or it may not be the best choice for you, but most people can take that option of getting the nasal spray if they really are anxious about getting the shot.
“We will definitely say, ‘If it means you end up getting a flu vaccine and you'd rather choose a nasal spray, get that nasal spray,’” she added. “It is typically pretty comparable to the shot in terms of effectiveness.”
Do it for yourself and others
“There are benefits to us as individuals: We're less likely to get the flu. Even if we do develop the flu, we're less likely to need to be hospitalized and it tends to be less severe if you get the vaccine,” said Dr. Kirley. “It is also about protecting others—your family, friends, community members.”
“The flu vaccine is most effective for all of us when more of us get it, so we can get closer to achieving—at least for flu season—that herd immunity,” she said. “Getting the flu shot is not just doing something for yourself, but it definitely is a way you can contribute to good health in your community.”
There are many ways to get it
“You have a lot of options in terms of where you can receive the flu shot. We usually suggest that people reach out to their primary care doctor's office first,” said Dr. Kirley. “Primary care physician offices usually have lots of options for how you can come in and get your flu shot, but there are other places as well.”
Vaccines are key to keeping everyone healthy and preventing infection. Visit vaccines.gov to learn more about where you can get a flu vaccine near you.
