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Common vaccination side-effects

Common vaccine side-effects

  • Pain, swelling, and/or redness in the arm where the vaccine was given (or thigh for small children)
  • Fever
  • Feeling tired
  • Headache
  • Nausea or loss of appetite
  • Fussiness or crying (small children)
  • Chills
  • Muscle or joint pain
  • Swollen lymph nodes
  • You may get vaccine side-effects in the first 2 days after getting a dose of the vaccine.
  • They may affect your ability to do daily activities but should go away within a few days.
  • Vaccine side effects are normal and show that your body is learning to fight the virus and build up immunity. Not everyone gets them side-effects.
  • Younger children may have fewer side effects after getting a COVID-19 vaccine than teens or young adults.
  • Side effects are more common after the second dose than the first. So far, side effects reported after getting a booster dose are like those after getting the primary doses.
  • It is important to get all recommended COVID-19 vaccine doses, even if you get side effects after a dose, unless a vaccination provider or your doctor tells you not to.

Contact your doctor if you have:

  • Redness or tenderness where the vaccine was given gets worse after 24 hours
  • Symptoms that get worse or worry you
If you or your child get a COVID-19 vaccine and you think you or they might be having a severe allergic reaction after leaving the vaccination site. Seek immediate medical care by calling 911 or go to the nearest emergency room. See severe allergic reactions to learn more.

Tips to help with vaccine side-effects

  • Apply a clean, cool, wet washcloth to reduce pain and discomfort in your arm. It may also help to use or exercise your arm. To reduce discomfort from fever, drink plenty of fluids and dress lightly.
  • Over-the counter medicines like acetaminophen (Tylenol®) or ibuprofen (Motrin or Advil®) can help if you develop pain, fever, headache, or discomfort.
Rare, serious side effects

Serious vaccine side effects are rare but may occur. For more information see Safety of COVID-19 Vaccines and Selected Adverse Events Reported after COVID-19 Vaccination.

Severe allergic reactions

As with any medicine, it is rare but possible to have a serious allergic reaction. A severe allergic reaction will usually occur within a few minutes to one hour after getting a vaccine. For this reason, your vaccination provider may ask you to stay at the place where you received your vaccine for monitoring. Signs of a severe allergic reaction can include:

  • Difficulty breathing or wheezing
  • Swelling of your tongue or throat
  • A rash or hives over your body
  • A fast heartbeat
  • Dizziness and weakness

It is very unlikely that this will happen. If it does, call 911 or go to the nearest emergency room.

Myocarditis & Pericarditis

There is a rare risk of inflammation of the heart muscle (myocarditis) or outer lining of the heart (pericarditis) in some people who got the Pfizer, Moderna, or Novavax vaccine.

Both myocarditis and pericarditis have the following symptoms:

  • Chest pain
  • Shortness of breath
  • Feelings of having a fast beating, fluttering, or pounding heart.

Myocarditis and pericarditis are more common after the second vaccine dose. But getting the second vaccine dose later (at 8 weeks) may lower the risk of these rare heart problems.

Most patients with myocarditis and pericarditis who received care improved with medicine and rest and felt better quickly.

Get medical care if you or your child have symptoms of myocarditis or pericarditis especially if it’s within a week after COVID-19 getting a vaccine.

It is important to note that getting COVID-19 is also connected with an increased risk of myocarditis and pericarditis. Plus, getting COVID is also linked with a higher risk of stroke, acute coronary syndrome, heart attack (myocardial infarction), heart failure, irregular heartbeat (arrhythmia), and cardiac death.

For more information, visit the CDC webpage Myocarditis and Pericarditis Following mRNA COVID-19 Vaccination.

Janssen / Johnson & Johnson (J&J) vaccine - This vaccine is no longer available in the US.

There have been rare cases of both Guillain Barré syndrome (a nervous system disorder) and thrombosis with thrombocytopenia syndrome (a condition with blood clots and low platelets) in people who got the J&J COVID-19 Vaccine. For more information on these rare conditions, see the CDC webpage Selected Adverse Events Reported after COVID-19 Vaccination.

How to report an adverse reaction (possible side-effect)

If you have an adverse event (possible side effect) after you are vaccinated,  even if you aren't sure that the vaccine caused it, please report it to VAERS. The Vaccine Adverse Event Reporting System is an early warning system that the FDA and CDC use to detect possible safety problems. To make a report, call 1-800-822-7967 or visit  https://vaers.hhs.gov/reportevent.html.  Please note that VAERS does not provide medical advice.

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Public Health has made reasonable efforts to provide accurate translation. However, no computerized translation is perfect and is not intended to replace traditional translation methods. If questions arise concerning the accuracy of the information, please refer to the English edition of the website, which is the official version.

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