What Are the Side Effects of COVID-19 Vaccines?

Common symptoms to expect after a shot. Plus, simple ways to alleviate discomfort

Rachel Nania,

AARP

Comments

En español

Published September 24, 2021

/ Updated October 21, 2024

vaccine injecting into a covid cell cartoon

Getty Images

The COVID-19 vaccines have been updated for the 2024-2025 respiratory virus season to more closely match the latest versions of the coronavirus that continue to spread and cause infections.

The mRNA vaccines from Pfizer-BioNTech and Moderna target the KP.2 “FLiRT” variant that contributed to the summer swell in cases, and the vaccine from Novavax targets its "parental strain," JN.1. While these two variants are no longer dominant in the U.S., their close relatives are, and doctors and researchers expect the updated shots will provide good protection against severe symptoms of COVID-19 heading into 2025.

“COVID is [still] circulating with us,” Centers for Disease Control and Prevention (CDC) Director Mandy Cohen, M.D., said in a news briefing. “So we need to continue to be vigilant.”

Health officials are recommending that everyone ages 6 months and older get the updated vaccine this fall — especially older adults who are at higher risk for complications from COVID-19. Here’s what you need to know about any possible side effects from the vaccines.

No surprises from common COVID vaccine side effects

According to the Food and Drug Administration (FDA), the common side effects that can accompany the updated 2024-2025 shots are in line with those of the previous versions.

“So, if you had a sore arm before, if you had a little bit of achiness, maybe a little low-grade fever, you can expect that to happen again,” Kristin Englund, M.D., an infectious disease specialist with Cleveland Clinic, said in a news release.

According to the CDC, the most commonly reported side effects of the COVID mRNA vaccines (from Moderna and Pfizer-BioNTech) are:

Pain, soreness, redness at injection site
Fatigue
Headache
Muscle pain
Joint pain
Chills
Fever
Nausea/vomiting (Moderna)

And the most commonly reported side effects of the Novavax COVID vaccine, which uses a different and more traditional protein-based technology, are:

Pain, soreness, redness, swelling at injection site
Fatigue
Headache
Muscle pain
Joint pain
Chills
Fever
Nausea/vomiting

Alleviating COVID vaccine side effects

The good news: If you’ve been vaccinated for COVID-19 — and millions of Americans have been — you likely already know what to expect and how your body may react.

“I think people also understand how to manage the side effects better in terms of drinking plenty of water prior to getting a vaccine, drinking plenty of water after you get the vaccine, taking it easy the next day,” Robert Weber, administrator for pharmacy services at the Ohio State University Wexner Medical Center and assistant dean for medical center affairs at the Ohio State University College of Pharmacy, told AARP.

Taking an over-the-counter pain reliever afterward can help manage any discomfort, he added. Just know it’s not advised to take these medicines ahead of time to try to prevent potential side effects. And applying a clean, cool, wet washcloth to the injection site can help to relieve pain or swelling on the arm where you got the shot, the CDC says.

Another tip: If your schedule allows, clear your calendar the day after your vaccine. “If you work during the week, you might want to get vaccinated on Friday or Saturday so that you don’t have to work when you’re not feeling great,” said Kawsar Talaat, M.D., an associate professor in the Department of International Health at the Johns Hopkins Bloomberg School of Public Health. “Just know that one day of not feeling well from the vaccine is far better than several days of not feeling well with COVID,” she added.

Find COVID-19 Vaccines in Your State

AARP's 53 state and territory COVID-19 vaccine guides can help you find vaccines near you and provide the latest answers to common questions about costs, eligibility and availability.

Not everyone experiences side effects after a COVID-19 vaccine; for most who do, symptoms tend to be mild to moderate and go away in a few days. That said, if your side effects are worrying or linger longer, it’s important to call your doctor. Serious reactions are rare, the CDC says, but they can happen.

Anaphylaxis, a severe type of allergic reaction that can occur after any type of vaccination, has occurred at a rate of approximately 5 cases per 1 million COVID-19 vaccine doses administered, the CDC reports. Cases of myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of the outer lining of the heart) have also been reported following COVID-19 vaccination, though mostly in younger age groups.

Vaccines are key to preventing severe illness

COVID-19 is still sending thousands of Americans to the hospital each week, the latest data shows, and public health experts say getting the updated vaccine can keep that number from swelling even more.

Keep in mind that older adults have access to two other tools that can help them avoid illness from respiratory viruses: the annual influenza (flu) vaccine and the newer RSV vaccine, which protects against complications from respiratory syncytial virus — a common bug that hospitalizes as many as 160,000 people 65 and older each year.

“We also know that you can get more than one virus at the same time and that people who do get multiple viruses tend to be sicker. And so, again, anything you can do to prevent infection is good,” Talaat said.

For those who do get flu or COVID-19 this year, antiviral treatments can help keep an infection from progressing to severe illness.

Editor’s note: This story has been updated to include new information on 2024-2025 COVID vaccines.

%{postComment}%

Rachel Nania is an award-winning health editor and writer at AARP.org, who covers a range of topics including diseases and treatments.