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V-Safe
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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.


Click here for information on staying up to date on COVID-19 vaccines.
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After you get a Pfizer or Moderna vaccine:
English | Español
After you get Pfizer vaccine
Children under 18
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Common vaccination side-effects

Common vaccine side-effects

  • Fever, chills, and muscle aches
  • Headache
  • Feeling tired
  • Sore or red arm
  • You may get vaccine side-effects in the first 2 days after getting the vaccine.
  • These side effects may affect your ability to do daily activities, but they should go away within a day or two.
  • For two-dose vaccines, side effects are more common after the second dose. It is important to get the second dose even if you got side effects after the first dose unless a vaccination provider or your doctor told you not to.
  • These vaccine side effects are normal and show that your body is learning to fight the virus and build up immunity. Not everyone gets these side-effects.

Contact your doctor if you have:

  • Vaccine side-effects that last more than 2 days,
  • Symptoms that start more than 2 days after you get the vaccine
  • Any of these symptoms: cough, shortness of breath, runny nose, sore throat, or new loss of taste or smell (as these are not vaccine side-effects)
  • Symptoms that get worse or worry you.

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

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
  • Swelling of your face and throat
  • A fast heartbeat
  • A bad rash all over your body
  • Dizziness and weakness

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:

  • Shortness of breath
  • Chest pain
  • Leg swelling
  • Persistent abdominal pain
  • Severe or persistent headaches
  • Blurred vision
  • Easy bruising or tiny blood spots under the skin beyond the site of the injection.

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:

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

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:

  • Weakness or tingling sensations, especially in the legs or arms, that’s worsening and spreading to other parts of the body
  • Trouble walking
  • Difficulty with facial movements, including speaking, chewing, or swallowing
  • Double vision or inability to move eyes
  • Difficulty with bladder control or bowel function
V-Safe
vSafe on a phone
vSafe banner saying: Get vaccinated. Get your smartphone. Get started with v-safe.

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.

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.

More information from the CDC
  • Interim Public Health Recommendations for Fully Vaccinated People webpage (detailed information)
  • When You’ve Been Fully Vaccinated webpage (basic information)

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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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