Common vaccine side-effects
Contact your doctor if you have:
Tips to help with vaccine 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:
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:
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.
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.