Skip to main content

Janssen COVID-19 Vaccine Side Effects

Generic name: sars-cov-2 (covid-19) ad26 vaccine, recombinant

Medically reviewed by Drugs.com. Last updated on Jun 17, 2022.

Note: This document contains side effect information about sars-cov-2 (covid-19) ad26 vaccine, recombinant. Some dosage forms listed on this page may not apply to the brand name Janssen COVID-19 Vaccine.

Applies to sars-cov-2 (covid-19) ad26 vaccine, recombinant: intramuscular suspension.

Intramuscular route (Suspension)

Thrombosis with Thrombocytopenia SyndromeThe Janssen COVID-19 Vaccine can cause thrombosis with thrombocytopenia syndrome (TTS) which may be life-threatening.TTS may involve thrombosis at unusual locations for a thrombus (ie, cerebral vein, visceral artery or vein, extremity artery, central artery or vein) or in an extremity vein or pulmonary artery.Among reported cases of TTS following administration of the Janssen COVID-19 Vaccine, symptoms began approximately one to two weeks after vaccination.Instruct Janssen COVID-19 Vaccine recipients to seek immediate medical attention for shortness of breath, chest pain, leg swelling, persistent abdominal pain, neurological symptoms (including severe or persistent headaches or blurred vision), or petechiae beyond the site of vaccination.The clinical course of TTS following administration of the Janssen COVID-19 Vaccine shares features with autoimmune heparin-induced thrombocytopenia. In individuals with suspected TTS, the use of heparin may be harmful and alternative treatments may be needed.Do not administer the Janssen COVID-19 Vaccine to individuals with a history of thrombosis with thrombocytopenia following the Janssen COVID-19 Vaccine or any other adenovirus-vectored COVID-19 vaccine.

Serious side effects

Along with its needed effects, sars-cov-2 (covid-19) ad26 vaccine, recombinant (the active ingredient contained in Janssen COVID-19 Vaccine) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur while taking sars-cov-2 (covid-19) ad26 vaccine, recombinant:

More common

  • Difficulty in moving
  • fever
  • headache
  • joint pain or swelling
  • muscle aches, cramping, pains, or stiffness
  • nausea
  • unusual tiredness or weakness

Incidence not known

  • Anxiety
  • black, tarry stools
  • bleeding gums
  • blood in the urine or stool
  • bloody nose
  • blue or pale skin
  • blurred vision
  • chest pain or discomfort
  • chills
  • confusion
  • continuing ringing or buzzing or other unexplained noise in the ears
  • cough
  • dizziness or lightheadedness
  • fainting
  • fast heartbeat
  • hearing loss
  • heavier menstrual periods
  • hives or welts, itching, skin rash
  • inability to move the arms and legs
  • numbness, weakness, or tingling in the arms or legs
  • pain, redness, or swelling in the arm or leg
  • pinpoint red spots on the skin
  • redness of the skin
  • seizures
  • slurred speech
  • stomach pain
  • sudden, severe weakness or numbness in the arm or leg
  • sudden loss of coordination
  • trouble breathing
  • unusual bleeding or bruising
  • vision changes
  • vomiting blood

Other side effects

Some side effects of sars-cov-2 (covid-19) ad26 vaccine, recombinant may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  • Pain, redness, or swelling at the injection site

More about Janssen COVID-19 Vaccine (sars-cov-2 (covid-19) ad26 vaccine, recombinant)

Professional resources

Related treatment guides

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.