Sign up for v-safe, the CDC after-vaccination health checker If you have a smart phone, please sign up at vsafe.cdc.gov to tell CDC about any side effects. Click here for more information.
Keep your white vaccine card safe - it is your official vaccination record! See vaccination records webpage for more details.
Common vaccine side-effects
Contact your doctor if you have:
Tips to help with vaccine side-effects
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.
Rare blood clots and low platelets
Blood clots involving blood vessels in the brain, abdomen, and legs along with low levels of platelets (blood cells that help your body stop bleeding), have occurred in some people who have received the Johnson & Johnson/Janssen COVID-19 vaccine. This condition is called thrombosis with thrombocytopenia syndrome (TTS). It has been reported in males and females across a wide age range, with most reports in females ages 30-49 years. Symptoms usually begin about one to two weeks after getting a vaccine. The chance of this happening is highly unlikely.
You should seek medical attention right away if you have any of the following symptoms after receiving the Johnson & Johnson vaccine:
Myocarditis & Pericarditis
There have been reports of inflammation of the heart muscle (myocarditis) or outer lining of the heart (pericarditis) in some people who got the Pfizer or Moderna vaccine. These reports are rare, and the risk of this happening is very low. Most of the cases were in male adolescents and young adults age 16 years or older and typically within several days after getting the vaccine.
Seek medical help right away if you have any of the following symptoms after receiving the Pfizer or Moderna Vaccine:
Most patients with myocarditis and pericarditis who received care improved with medicine and rest and felt better quickly. Those who experience these conditions can usually return to their normal daily activities after their symptoms improve, and they should speak with their doctor about return to exercise or sports.
For more information, visit the CDC webpage Myocarditis and Pericarditis Following mRNA COVID-19 Vaccination.
Guillain Barré Syndrome
There have been reports of Guillain Barré syndrome in some people who got the Johnson & Johnson (Janssen) COVID-19 Vaccine. Guillain Barré syndrome is a nervous system disorder in which the body’s immune system damages nerve cells, causing muscle weakness and sometimes paralysis. In most of these people, symptoms began within 42 days of getting the vaccine. The chance of this happening is very low.
Seek medical attention right away if you develop any of the following symptoms after receiving the Johnson & Johnson Vaccine:
Help CDC learn more about the safety of COVID-19 vaccines. Use your smart phone to tell CDC about any side effects after getting the COVID-19 vaccine. You’ll also get reminders if you need a second vaccine dose.
Sign up at vsafe.cdc.gov
During the first week after you get your vaccine, v-safe will send you a text message each day to ask how you are doing. Then you will get check-in messages once a week for up to 5 weeks. You’ll also receive check-ins 3, 6, and 12 months after your final dose of vaccine. If you report certain symptoms, someone from CDC may call to check on you. Learn more about v-safe.
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.