The CDC Says These 3 Side Effects Mean Your Vaccine Is Working

With the COVID vaccine becoming available to more people by the day, many people are eager to know how the vaccine will affect them—and how they can tell the vaccine is working. Luckily, there's an easy way to tell if the vaccine is taking effect, according to experts from the Centers for Disease Control and Prevention (CDC). On Feb. 12, Amanda Cohn, MD, CAPT, USPHS, a member of the CDC's National Center for Immunization and Respiratory Diseases, announced that there are three specific side effects that people should look out for after receiving their vaccine. Read on to find out what they are, and for an update on when you'll be able to get your shot, check out Dr. Fauci Says You'll Easily Get a Vaccine Appointment After This Date.


Pain at the injection site

The first side effect Cohn called out was pain at the injection site. "People should be prepared to have pain," she warned, referring to the spot where you got your shot.

During a recent interview with medical professionals and officials from Prince George's County, Maryland, White House COVID adviser Anthony Fauci, MD, said he also experienced this side effect after both doses of the COVID-19 vaccine. "If I pressed on it, I felt a little ache on the arm," he explained. For Fauci, the side effect lasted just over 24 hours. And for the latest COVID news delivered straight to your inbox, sign up for our daily newsletter.



Cohn said fatigue is another indicator that your immune system is doing its job after you get vaccinated. While Fauci didn't experience this after his first shot, he did get worn out in the wake of his second dose. "Towards the evening, I started to feel a bit fatigued," he said. And if you're eager to get vaccinated, know that If You Live in These States, You Can Now Get Vaccinated at Walgreens.


Low-grade fever

The last side effect Cohn called out was a low-grade fever, which means anything below 100.4 degrees Fahrenheit. Though Fauci didn't personally experience this side effect from his COVID vaccinations, he acknowledged that some other recipients might. "It has occurred in some people," he said. And for more advice from the CDC, check out The CDC Says Don't Go to These 4 Places Without a Better Mask.


These are all more common after the second dose.

According to Cohn, all of these side effects should resolve within two days. As was Fauci's experience, Cohn noted that even if you don't have a reaction to the vaccine immediately after your first dose, that doesn't necessarily mean you're out of the woods. "People do have mild reactions to the vaccines, especially after the second dose," she explained.

And while the post-vaccine side effects may be uncomfortable, Cohn assured that they're nothing to worry about, and they're not signs that you've been infected with the virus itself. "It's not COVID. It's your body building an immune response to the protein that is mimicking the disease," she said. And for more on the signs that do mean something is amiss, check out If You Have These Vaccine Side Effects, Don't Get Another Shot, CDC Says.