You can get an updated flu vaccine now. Should you roll up your sleeve — or is it better to hold off? Here’s the best time to get your shot, plus more important info.
Updated vaccines aimed at the coming flu season are at pharmacies, doctor’s offices, and community clinics now. Should you claim your flu shot or nasal flu vaccine right away? Or are you worried it’s too soon and your immunity might “wear off” by the time flu season kicks into high gear?
Read on for advice about the best time to get immunized, plus other details like whether it’s safe to get the flu and COVID vaccines at the same time.
When’s the Best Time to Get a Flu Shot?
In a perfect world, you’d get your flu shot in October, says Scott Roberts, MD, infectious disease specialist and associate medical director of infection prevention at the Yale School of Medicine in New Haven, Connecticut.
“This ensures peak immunity against the virus occurs during months when the virus is typically at its peak — December and January — and when exposure risk is highest due to traveling and gathering for the holidays,” Dr. Roberts says.
His recommendation is in line with the Centers for Disease Control and Prevention (CDC) which advises getting the flu vaccine in September or October.
Just be sure to get vaccinated well before flu season really kicks in, if possible. “Thousands of people in the U.S. die every year from the flu or flu-related complications,” Roberts says.
If You Get the Flu Shot Too Early, Can It Wear Off Too Soon?
There is some truth to the concept that the flu shot can lose its effectiveness over time, says Frederick Chen, MD, MPH, primary care doctor and professor of family medicine at the University of Washington School of Medicine in Seattle.
“In general, we don’t recommend people getting the flu shot in July or August. It’s a good idea to wait until the middle of September,” says Dr. Chen.
There are a few exceptions to the rule, per the CDC:
Pregnant women in their third trimester can get a flu shot in July or August to ensure that their babies are protected after birth.
Children who need two doses of the flu vaccine should get their first dose as soon as it becomes available, with the second dose given at least four weeks later.
Vaccination in July or August can be considered for children who have back-to-school doctor appointments and might not return to see a healthcare provider in September or October.
Can I Wait to See if There’s Lots of Flu Where I Live Before Getting Vaccinated?
Trying to sync your flu shot with flu activity in your area is not only difficult, it may also leave you vulnerable. The virus can start spreading at any time, and that can be hard to predict.
Keep in mind it takes about two weeks for the vaccine to take full effect.
Is It Ever Too Late to Get the Flu Vaccine?
It’s never too late to get a flu shot, says Chen. As long as flu viruses are still circulating, it’s still worth getting vaccinated, even if it’s February or March.
“This year, it’s recommended that you get the flu shot in the fall, but if for some reason you wait until later in the season, you should still get it,” he adds.
How Effective Will This Year’s Flu Vaccine Be?
Each year, an advisory committee to the U.S. Food and Drug Administration (FDA) reviews and updates the composition of U.S. flu vaccines to best match the viral strains expected to be the most common during the upcoming season.
The vaccine’s effectiveness depends on the accuracy of this match, and it’s too early to know exactly how good this year’s prediction will be.
For the 2023–24 season, the vaccine was 41 to 44 percent effective in preventing flu-related hospitalization in adults and 52 percent to 61 percent effective for children.
“Despite not being perfect, the data show that vaccination is one of the best ways to protect yourself against seasonal influenza,” says Tony Moody, MD, professor of pediatrics, infectious diseases at Duke University School of Medicine in Durham, North Carolina, and director of the Duke CIVICs Vaccine Center.
Can I Get a Flu and COVID-19 Vaccine at the Same Time?
Yes, you can receive a flu and COVID-19 vaccine (and an RSV vaccine, if you are eligible) during the same healthcare visit, says the CDC.
What Are the Most Common Side Effects of the Flu Shot?
A sore arm at the injection site, headache, fever, nausea, muscle aches, and fatigue are the most common flu shot side effects. These are generally mild and go away on their own within a day or two.
Should I Be Worried About a Flu Vaccine Shortage?
The flu vaccine is produced by private manufacturers, and so supply depends on those companies. Those manufacturers have projected that they will provide the United States with about 148 million flu doses for 2024–2025.
Currently, there are no delays, and the vaccine is already available.
Is It Really Okay to Get a Flu Shot at a Pharmacy or Grocery Store?
Yes, it’s perfectly safe to get your flu shot at your local pharmacy or grocery store, says Chen.
The online directory VaccineFinder can show you locations in your area that offer flu vaccines. Note that these are free with most insurance.
Is the Flu Season Expected to Be Bad This Year?
Experts often look at flu rates in the Southern Hemisphere to project what the season might be like in the United States.
That data suggests that the flu will continue to pose a significant threat, causing many illnesses, hospitalizations, and deaths across the globe.
The Southern Hemisphere influenza season was similar to past seasons in scope and severity, says Michael Ben-Aderet, MD, associate medical director of hospital epidemiology at Cedars-Sinai in Los Angeles.
“Some nations had higher severity than others, which is normal. In Australia, for example, we saw a trend similar to the prior year, and in-line with pre-pandemic averages. I think we can expect something similar in the Northern Hemisphere this season,” says Dr. Ben-Aderet.
Is It True That Getting a Flu Shot Can Give You the Flu?
Most years only about half of Americans get flu shots, notes Chen. “The most common reason that I hear about why people don’t want a flu shot is that they got a flu shot once and got the flu afterward,” he says. “Let me be clear: Flu shots do not give you the flu.”
Flu vaccines do vary in how well they work, so people who are vaccinated can still get sick. But even if that happens, research shows that the vaccine can still help by reducing flu severity.
The Takeaway
The best month to get a flu vaccine in the US is September or October, which means you will be protected throughout the flu season and especially during the peak period of December and January.
But it’s never too late to get vaccinated, even if that means February or March, to protect against potentially severe illness.
Jane Yoon Scott, MD, is an infectious disease physician and an assistant professor of medicine at Emory University in Atlanta. Dr. Scott enjoys connecting with her patients, empowering them to understand and take ownership of their health, and encouraging them to ask questions so that they can make informed and thoughtful decisions.
She graduated with the highest honors from the Georgia Institute of Technology, then received her MD from the Medical College of Georgia. She completed her internal medicine residency training and chief residency at Temple University Hospital, as well as a fellowship in infectious diseases at Emory University. She is board-certified in both internal medicine and infectious diseases.
When she is not seeing patients, Dr. Scott works with neighboring health departments to promote public health, especially to communities that have been historically underserved. She also teaches medical trainees and lectures medical students at the Emory University School of Medicine.
In her free time, Dr. Scott appreciates a good coffee shop, weekend hikes, playing guitar, strolling through cities, sampling restaurants, and traveling to new places.
Becky Upham has been professionally involved in health and wellness for almost 20 years. She's been a race director, a recruiter for Team in Training for the Leukemia & Lymphoma Society, a salesperson for a major pharmaceutical company, a blogger for Moogfest, a communications manager for Mission Health, a fitness instructor, and a health coach.
She majored in English at the University of North Carolina and has a master's in English writing from Hollins University.
Upham enjoys teaching cycling classes, running, reading fiction, and making playlists.
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
Grohskopf, LA et al. Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices — United States, 2024-25 Influenza Season. Morbidity and Mortality Weekly Report (MMWR). August 29, 2024.
