People around the United States are beginning to receive COVID-19 vaccines.

The Food and Drug Administration granted emergency use authorization to two vaccines, one developed by Pfizer-BioNTech and one developed by Moderna. Distribution began in December 2020. Both the Pfizer and Moderna vaccines require two doses to be fully effective.

A third vaccine, developed by Johnson & Johnson/Janssen, received EUA in February 2021. The J&J vaccine currently requires one dose.

You may be familiar with other vaccines. However, you should follow certain steps after receiving the COVID-19 vaccine.

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Does the COVID-19 Vaccine Have Side Effects?

Reported data from the vaccines’ clinical trials show they are safe and effective. Serious side effects are rare.

When you receive the vaccine, you will be monitored for an allergic reaction for 15 to 30 minutes after injection. Allergic reactions to the vaccine are rare.

The most common side effects to the vaccine include:

  • Injection site pain/redness/swelling
  • Arm soreness
  • Fatigue
  • Fever or feverishness
  • Chills
  • Body/joint/muscle aches
  • Headaches

If you have side effects, you can use ibuprofen or acetaminophen as recommended by your care provider. If you have a sore arm, apply an ice pack to ease the discomfort.

According to the Centers for Disease Control and Prevention (CDC), you should contact your doctor if pain or redness at the injection site increases after 24 hours. You should also contact your doctor if your symptoms aren’t going away after a few days.

Do You Still Need to Wear a Mask After Getting the COVID-19 Vaccine?

In short, yes.

Like any vaccine, it takes time for your body to build up protection after vaccination. The COVID-19 vaccine’s full potency doesn’t take effect until after the second dose.

According to reported data from the Pfizer and Moderna vaccines, both are at least 94% effective in preventing symptomatic COVID-19. The J&J vaccine is about 70% effective in preventing mild to moderate COVID-19 and 85% in preventing severe illness.

It is still possible to get COVID-19 after being vaccinated.

It is also not yet known whether getting a COVID-19 vaccine will prevent you from spreading the coronavirus to other people.

You should continue to follow CDC public health recommendations after receiving both the first dose and second dose of the Moderna and Pfizer vaccines. Those recommendations include:

  • Wearing a facemask over your nose and mouth when around people who are not from your household, especially in public
  • Avoiding large gatherings or crowds
  • Avoiding poorly ventilated places
  • Maintaining at least six feet of social distance from others
  • Following hand hygiene

When Do I Get the Second Dose of the COVID-19 Vaccine?

You should get the second dose at least 21 days (for Pfizer-BioNTech) or at least 28 days (for Moderna) after your first dose.

If the second dose is delayed beyond 21 or 28 days, it will still be effective. The CDC says you can get the second dose of the Pfizer and Moderna vaccines up to 42 days after the first dose.

When you get your first dose of the Pfizer or Moderna vaccine, talk to your health provider about scheduling the second dose.

Where Can I Go for COVID-19 Vaccine Information?

For information about COVID-19 vaccination at UPMC, visit

Use the CDC’s “v-safe” smartphone tool to report side effects or other concerns to the CDC; someone may contact you for more information. The tool also will remind you to get the second dose of the vaccine. Visit to register.


Centers for Disease Control and Prevention, What to Expect After Getting a COVID-19 Vaccine. Link

About UPMC

A $21 billion health care provider and insurer, Pittsburgh-based UPMC is inventing new models of patient-centered, cost-effective, accountable care. The largest nongovernmental employer in Pennsylvania, UPMC integrates more than 90,000 employees, 40 hospitals, 700 doctors’ offices and outpatient sites, and a 3.8 million-member Insurance Services Division, the largest medical insurer in western Pennsylvania. In the most recent fiscal year, UPMC contributed $1.4 billion in benefits to its communities, including more care to the region’s most vulnerable citizens than any other health care institution, and paid more than $500 million in federal, state, and local taxes. Working in close collaboration with the University of Pittsburgh Schools of the Health Sciences, UPMC shares its clinical, managerial, and technological skills worldwide through its innovation and commercialization arm, UPMC Enterprises, and through UPMC International. U.S. News & World Report consistently ranks UPMC Presbyterian Shadyside on its annual Honor Roll of America’s Best Hospitals and ranks UPMC Children’s Hospital of Pittsburgh on its Honor Roll of America’s Best Children’s Hospitals. For more information, go to