COVID-19 Vaccine Side Effects: What you need to know

By Heather Grey

In December 2020, the Food and Drug Administration (FDA) issued emergency use authorizations (EUAs) for two vaccines against COVID-19 — one produced by Pfizer and BioNTechTrusted Source, and one by ModernaTrusted Source.

Now the FDA is reviewing another EUA request for a vaccine developed by Johnson & Johnson’s subsidiary company, Janssen Biotech.

All these vaccines appear to have mostly mild side effects that over-the-counter pain relievers can treat.

In rare cases, severe allergic reactions have been reported, but in all those cases, people were successfully treated.

If the FDA finds that Johnson & Johnson’s vaccine is safe and effective enough to distribute, that will drastically increase the stock of vaccine doses in the country.

“We are looking forward to it becoming available so that our vaccine supply can grow and synchronize with the demand,” said Dr. David Hirschwerk, an infectious disease specialist at Northwell Health in Manhasset, New York.

“But the FDA is extremely rigorous in their reviews. They will comb through the data methodically,” he said, “and are committed to seeing efficacy and safety demonstrated prior to issuing an [EUA].”

Safe vaccines have some mild side effects

Before issuing EUAs for the Pfizer-BioNTech and Moderna COVID-19 vaccines, the FDA reviewed the available data from ongoing clinical trials.

Pfizer-BioNTech submitted data for people 16 years and older, while Moderna submitted findings for people 18 years and older.

The most common reported side effect following vaccination is pain at the injection site.

Some vaccine recipients also developed short-lived flu-like symptoms, such as fatigue, headache, body aches, chills, and fever.

Swollen lymph nodes have also been reported. These can appear as a lump in the armpit, which has worried some women who thought it could be a sign of breast cancer.

Trial data has shown that two doses of the Pfizer-BioNTech vaccine are 95 percent effective at preventing COVID-19, while two doses of the Moderna vaccine are 94 percent effective.

The trials have also found that both vaccines are safe and generally well tolerated.

“The side effect profile for both vaccines was very favorable,” Dr. Miriam Smith, the chief of infectious disease at Long Island Jewish Forest Hills in Queens, New York, told Healthline.

Anaphylaxis is rare and treatable

Anaphylaxis is a severe allergic reaction that can result from the vaccinations. It can be life threatening when not treated.

Since issuing EUAs for the Pfizer-BioNTech and Moderna vaccines, the federal government has continued to collect information about reported side effects, including rare cases of anaphylaxis or severe allergic reactions following vaccination.

The reported rateTrusted Source of anaphylaxis following vaccination with the Pfizer-BioNTech COVID-19 vaccine is 4.7 cases per million, while the reported rate for the Moderna vaccine is 2.5 cases per million.

No deaths from anaphylaxis following either vaccine have been reported.

Additional vaccines in the pipeline

Additional COVID-19 vaccines may soon become available in the United States, including vaccines from Johnson & Johnson and Oxford-AstraZeneca.

Johnson & Johnson submitted an EUA request for its vaccine on Feb. 4, and the FDA’s Vaccines and Related Biological Products Advisory Committee is scheduledTrusted Source to discuss later this EUA this month.

Researchers at AstraZeneca and Oxford University have also developed a vaccine against COVID-19. This vaccine has already been approved for use in the United Kingdom and several other countries, but the developers may not be ready to submit an EUA request to the FDA until this spring.

The Johnson & Johnson and Oxford-AstraZeneca vaccines appear to be somewhat less effective than the Pfizer-BioNTech and Moderna vaccines, but they have similar safety profiles and reported side effects such as sore arm, fever, or chills.

“These vaccines also appear to be very safe and also demonstrate injection site soreness as the main side effect,” Hirschwerk said.

Weighing the benefits and risks

If you have certain health conditions, such as a history of severe allergic reaction to vaccines, your doctor may advise you not to get the COVID-19 vaccine.

But for most people, Hirschwerk said the benefits of getting vaccinated against COVID-19 “far outweigh” the risks.

“At this point, over 30 million Americans have received at least a single dose, and it has been very well tolerated and very effective,” he said.

“Severe side effects like anaphylaxis have proven to be extremely rare and, of course, are treatable,” he continued.

If you develop pain around the injection site after getting vaccinated, Smith said that applying ice or taking an over-the-counter pain reliever may help.

To ease flu-like symptoms following vaccination, she recommends taking anti-fever medication or a nonsteroidal anti-inflammatory drug (NSAID).

If you think you might be experiencing a severe allergic reaction to the vaccine, the Centers for Disease Control and PreventionTrusted Source recommends calling 911 or local emergency services for immediate medical attention.

Healthline