Coronavirus Disease 2019 (COVID-19) Vaccine Safety

Key points

  • Coronavirus disease 2019, or (COVID-19), is a respiratory disease caused by the SARS-CoV-2 virus.
  • COVID-19 vaccines can help reduce the risk of illness from COVID-19 and its potentially serious complications.

Overview

COVID-19 spreads mainly from person-to-person through respiratory droplets produced when an infected person coughs, sneezes, or talks. Some people who are infected may not have symptoms. For people who have symptoms, illness can range from mild to severe.

Fact‎

COVID-19 vaccines can help reduce the risk of illness from COVID-19 and its potentially serious complications.

Available vaccines & manufacturer package inserts

Pfizer-BioNTech (Comirnaty®) and Moderna (Spikevax®)

  • Approved for use or authorized for emergency use by the FDA in the United States.
  • mRNA vaccines that use mRNA created in a laboratory to teach cells how to make a protein that triggers an immune response inside the body.
  • Authorized for children ages 6 months through 11 years and approved for people ages 12 years and older.

Novavax

  • A protein subunit vaccine that contains spike proteins of the virus that causes COVID-19. After learning how to respond to the spike protein, the immune system will respond quickly to protect against the actual COVID-19 virus.
  • Authorized for people 12 years and older.

Fact‎

These vaccines have been updated for 2023-2024 to protect against circulating variants of the virus that causes COVID-19.

Manufacturer package inserts and factsheets

Fully licensed FDA vaccines

  • FDA approved Comirnaty in 2021. It is approved for use in people 12 years of age and older. This is a single dose injection.
  • FDA approved Spikevax in 2022. It is approved for use in people 12 years of age and older.

Emergency use authorization vaccines

Keep Reading: Vaccine Information Statements

Who should & should not get the vaccine

CDC recommends that people receive the age-appropriate vaccine product and dosage based on their age on the day of vaccination.

Learn information about COVID-19 vaccination, recommendations, provider requirements and support, or who should and should not get vaccinated.

Common side effects

The most common side effects are usually mild, such as soreness in the area where the shot was given. Vaccines, like any medicine, can have side effects. Side effects after getting a COVID-19 vaccine vary from person to person.

mRNA vaccines (Pfizer-BioNTech and Moderna)

  • Pain, soreness, redness at injection site.
  • Fatigue.
  • Headache.
  • Muscle pain.
  • Joint pain.
  • Chills.
  • Fever.
  • Nausea/vomiting (Moderna).
  • In infants and toddlers, common symptoms include irritability or crying, decreased appetite, and sleepiness.

Protein subunit vaccine (Novavax)

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

Keep in mind‎

If you experienced side effects within 4 hours of getting a COVID-19 vaccine (such as a red, itchy, swollen, or painful rash where you got the shot, also known as "COVID arm"), you likely can receive another dose of the same type of vaccine under certain conditions, such as getting your next vaccine in the opposite arm or being observed in the clinic for 30 minutes after vaccination. Your doctor may refer you to an allergy and immunology specialist for additional care or advice.

Everyone who gets a COVID-19 vaccine may be monitored onsite for at least 15 minutes after vaccination (people who experience or have experienced non-severe allergic reactions to COVID vaccines may be monitored for 30 minutes).

Severe allergic reactions

Severe allergic reactions following vaccination are rare but can be life threatening. Symptoms of a severe allergic reaction may include:

  • Anaphylaxis, which is a life-threatening reaction that needs to be treated with epinephrine (EpiPen) and may require hospitalization. Symptoms include wheezing, difficulty breathing, or low blood pressure; and sometimes hives.
  • Swelling of the airway, which includes the tongue, uvula, or larynx.
  • A widespread rash involving the skin and inside places like your mouth or nose that required hospitalization.

When to seek emergency care‎

If someone experiences symptoms of a severe allergic reaction, which can include hives, swelling of the face and throat, difficulty breathing, a fast heartbeat, dizziness, and weakness. Severe allergic reactions following vaccination are rare, but can be life threatening.

If you had a severe allergic reaction after receiving a particular type of COVID-19 vaccine (either mRNA or Novavax), you should not get another dose of that type of vaccine. You will likely be able to receive the alternate vaccine type. Your doctor may refer you to an allergy and immunology specialist for additional care or advice.

In rare cases, people have experienced serious health events after COVID-19 vaccination. An adverse event (any side effect or health problem after vaccination that is concerning to you, even if you are not sure if the vaccine caused the event) can be caused by the vaccine or be a coincidental event that is not related to the vaccine, such as an unrelated fever, that happened following vaccination.

Report possible adverse events to VAERS‎‎
‎

The Vaccine Adverse Event Reporting System (VAERS) is an early warning system, co-managed by CDC and FDA, that monitors for potential vaccine safety problems. Healthcare providers and vaccine manufacturers are required by law to report certain adverse events following vaccination to VAERS; patients and caregivers can also submit reports.
Submitting a Vaccine Adverse Event Reporting System (VAERS) Report and Using VAERS Data

A closer look at the safety data

Fact‎

COVID-19 vaccines have undergone the most extensive safety analysis in U.S. history.

COVID-19 vaccines meet the FDA's standards for safety and effectiveness.12345678910111213

Anaphylaxis, myocarditis, and pericarditis

To date, the systems in place to monitor the safety of these vaccines have found two serious types of adverse events following COVID-19 vaccination. The two serious adverse events following COVID-19 vaccination currently used in the United States are anaphylaxis and myocarditis or pericarditis.

  • Anaphylaxis is a severe type of allergic reaction that can rarely happen after any vaccine. Anaphylaxis needs to be treated with epinephrine (for example, EpiPen) and may require hospitalization. Anaphylaxis can involve wheezing, difficulty breathing, or low blood pressure; and sometimes is accompanied by hives. Anaphylaxis after COVID-19 vaccination is rare.145711141516
    • It has occurred at a rate of approximately 5 cases per one million vaccine doses administered. Anaphylaxis, a severe type of allergic reaction, can occur after any kind of vaccination. If it happens, healthcare providers can effectively and immediately treat the reaction.
  • Myocarditis is inflammation of the heart muscle, and pericarditis is inflammation of the outer lining of the heart. Myocarditis and pericarditis after COVID-19 vaccination are rare.1234567911121718192021 Most patients with myocarditis or pericarditis after COVID-19 vaccination responded well to medicine and rest and felt better quickly.
  • Pericarditis is inflammation of the outer lining of the heart. Most patients with pericarditis after COVID-19 vaccination responded well to medicine and rest and felt better quickly, and most cases have been reported after receiving mRNA COVID-19 vaccines.
    • Pericarditis after COVID-19 vaccination are rare.171920

The evidence suggests that, although rare, these events are linked to certain types of COVID-19 vaccinations that were administered. Healthcare providers should review additional recommendations and clinical guidance on myocarditis considerations.

Investigating long-term effects of myocarditis

  • CDC is contacting people (or their parents or guardians) who meet the case definition for myocarditis (i.e., have symptoms of myocarditis and medical tests to support its diagnosis and rule out other causes) following COVID-19 vaccination in VAERS.
  • CDC may contact your healthcare provider for information on medications you take and your test results.
  • Personal information and responses will be kept private to the extent allowable under the law. If the patient is a minor, a parent or legal guardian will be invited to participate on their behalf.
    • The person's name and any identifying information will not be included in any reports.
  • Initial patient surveys showed nearly all patients (80%) were considered by their cardiologist or other healthcare provider to have either fully or probably fully recovered.22

Guillain-Barré Syndrome (GBS)

Based on an analysis of data from the Vaccine Safety Datalink (VSD), the rate of GBS within the first 21 days following J&J/Janssen COVID-19 vaccination was found to be 21 times higher than after Pfizer-BioNTech or Moderna (mRNA) COVID-19 vaccination. After the first 42 days, the rate of GBS was 11 times higher following J&J/Janssen COVID-19 vaccination. The analysis found no increased risk of GBS after Pfizer-BioNTech or Moderna vaccination.

Similarly, CDC found higher than expected rates of GBS reported to VAERS after J&J/Janssen COVID-19 vaccination but not after mRNA COVID-19 vaccination. These observations contributed to the preferential recommendation by the Advisory Committee on Immunization Practices (ACIP) to use mRNA COVID-19 vaccines over the J&J/Janssen COVID-19 vaccine, which is no longer available in the United States.

Thrombosis with Thrombocytopenia Syndrome (TTS)

Thrombosis with thrombocytopenia syndrome (TTS) has been rarely observed after J&J/Janssen COVID-19 vaccination and has occurred in approximately 4 cases per one million doses administered. TTS is a rare but serious adverse event that causes blood clots in large blood vessels and low platelets (blood cells that help form clots).

A review of reports indicates a causal relationship between the J&J/Janssen COVID-19 vaccine and TTS. This observation contributed to the preferential recommendation by ACIP to use mRNA COVID-19 vaccines over the J&J/Janssen COVID-19 vaccine, which is no longer available in the United States.23242526

Reports of deaths

Multiple factors contribute to reports of death after COVID-19 vaccination, including heightened public awareness of COVID-19 vaccines, requirements under FDA authorization for COVID-19 vaccines that healthcare providers report any death after COVID-19 vaccination to VAERS (even if it is unclear whether the vaccine was the cause), and reporting requirements in CDC vaccine provider agreements. People receiving COVID-19 vaccines are less likely to die from COVID-19 and its complications and are at no greater risk of death from non-COVID causes, than unvaccinated people.27282930

How CDC monitors vaccine safety

CDC and the Food and Drug Administration (FDA) are committed to ensuring that vaccines provided to the public are safe and effective. Once vaccines are licensed or authorized for emergency use in the United States, CDC and FDA continuously monitor them through several safety systems.

Keep Reading: About CDC's Vaccine Safety Monitoring Program

Resources

Who Should NOT Get Vaccinated with these Vaccines?
Who should NOT Get Vaccinated?
COVID-19 ACIP Vaccine Recommendations
ACIP Recommendations on Influenza and other MMWR articles. Advisory Committee on Immunization Practi...
CDC COVID-19 Vaccination Program Provider Requirements and Support
Requirements and support for COVID-19 vaccination providers participating in the CDC COVID-19 Vaccin...
Contraindications and Precautions
Contraindications and Precautions: General Best Practice Guidelines for Immunization. Advisory Commi...
Immunization Schedules
Stay up-to-date on getting recommended vaccines. Here are immunization schedules for people of all a...
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Content Source:
National Center for Emerging and Zoonotic Infectious Diseases (NCEZID)
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