URL of this page: https://medlineplus.gov/druginfo/meds/a621007.html

COVID-19 Vaccine, Viral Vector (Janssen)


The Janssen coronavirus disease 2019 (COVID-19) vaccine is currently being studied to prevent coronavirus disease 2019 caused by the SARS-CoV-2 virus. There is no FDA-approved vaccine to prevent COVID-19.

Only limited clinical trial information is available at this time to support the use of Janssen COVID-19 vaccine to prevent COVID-19. In clinical trials, approximately 21,895 individuals 18 years of age and older have received the Janssen COVID-19 vaccine. More information is needed to know how well Janssen COVID-19 vaccine works to prevent COVID-19 and the possible adverse events from it.

Janssen COVID-19 vaccine has not undergone the standard review to be approved by the FDA for use. However, the FDA has approved an Emergency Use Authorization (EUA) to allow certain adults 18 years of age and older to receive it.

Talk to your doctor about the risks and benefits of receiving this medication.

What is COVID-19?

COVID-19 disease is caused by a coronavirus called SARS-CoV-2. This type of coronavirus has not been seen before. You can get COVID-19 through contact with another person who has the virus. It is predominantly a respiratory (lung) illness that can affect other organs. People with COVID-19 have had a wide range of symptoms reported, ranging from mild symptoms to severe illness. Symptoms may appear 2 to 14 days after exposure to the virus. Symptoms may include: fever, chills, cough, shortness of breath, fatigue, muscle or body aches, headache, loss of taste or smell, sore throat, congestion, runny nose, nausea, vomiting, or diarrhea.

How is the Janssen COVID-19 vaccine given?

The Janssen COVID-19 vaccine will be given to you as an injection into the muscle. The Janssen COVID-19 vaccine vaccination is given as a one-time dose.

What should you tell the person who is giving the vaccine?

Tell your vaccine provider about all of your medical conditions, including if you:

  • have any allergies.
  • have a fever.
  • have a bleeding disorder or are on a blood thinner such as warfarin (Coumadin, Jantoven).
  • are immunocompromised (weakened immune system) or are on a medicine that affects your immune system.
  • are pregnant or plan to become pregnant.
  • are breastfeeding.
  • have received another COVID-19 vaccine.
  • have had a serious allergic reaction to any ingredient in this vaccine.

What are the benefits of the Janssen COVID-19 vaccine?

In an ongoing clinical trial, the Janssen COVID-19 vaccine has been shown to prevent COVID-19 after a single dose. How long you are protected against COVID-19 is currently unknown.

What are the risks of the Janssen COVID-19 vaccine?

Side effects that have been reported with the Janssen COVID-19 vaccine include:

  • injection site pain, swelling, and redness
  • tiredness
  • headache
  • muscle pain
  • joint pain
  • chills
  • nausea
  • fever

There is a remote chance that the Janssen COVID-19 vaccine could cause a severe allergic reaction. A severe allergic reaction would usually occur within a few minutes to one hour after getting a dose of the Janssen COVID-19 vaccine.

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

These may not be all the possible side effects of the Janssen COVID-19 vaccine. Serious and unexpected side effects may occur. Janssen COVID-19 vaccine is still being studied in clinical trials.

What should I do about side effects?

  • If you experience a severe allergic reaction, call 9-1-1 or go to the nearest hospital.
  • Call the vaccination provider or your healthcare provider if you have any side effects that bother you or do not go away.
  • Report vaccine side effects to FDA/CDC Vaccine Adverse Event Reporting System (VAERS). The VAERS toll-free number is 1-800-822-7967, or report online to https://vaers.hhs.gov/reportevent.html. Please include "Janssen COVID-19 Vaccine EUA" in the first line of box #18 of the report form.
  • In addition, you can report side effects to Janssen Biotech, Inc. at 1-800-565-4008 or JNJvaccineAE@its.jnj.com.
  • You may also be given an option to enroll in v-safe. V-safe is a new voluntary smartphone-based tool that uses text messaging and web surveys to check in with people who have been vaccinated to identify potential side effects after COVID-19 vaccination. V-safe asks questions that help CDC monitor the safety of COVID-19 vaccines. V-safe also provides live telephone follow-up by CDC if participants report a significant health impact following COVID-19 vaccination. For more information on how to sign up, visit: http://www.cdc.gov/vsafe.

Will the Janssen COVID-19 vaccine give me COVID-19?

No. The Janssen COVID-19 vaccine does not contain SARS-CoV-2 and cannot give you COVID-19.

Keep your vaccination card

When you get your dose, you will get a vaccination card.

Where will my vaccination information be recorded?

The vaccination provider may include your vaccination information in your state/local jurisdiction's Immunization Information System (IIS) or other designated system. For more information about IISs visit: https://www.cdc.gov/vaccines/programs/iis/about.html.

How can I learn more?

The Countermeasures Injury Compensation Program

The Countermeasures Injury Compensation Program (CICP) is a federal program that may help pay for costs of medical care and other specific expenses of certain people who have been seriously injured by certain medicines or vaccines, including this vaccine. Generally, a claim must be submitted to the CICP within one year from the date of receiving the vaccine. To learn more about this program, visit http://www.hrsa.gov/cicp/ or call 1-855-266-2427.

The American Society of Health-System Pharmacists, Inc. represents that this information about the Janssen COVID-19 vaccine was formulated with a reasonable standard of care, and in conformity with professional standards in the field. Readers are cautioned that the Janssen COVID-19 vaccine is not an approved vaccine for coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2, but rather, is being investigated for and is currently available under an FDA emergency use authorization (EUA) to prevent COVID-19 in certain adults. The American Society of Health-System Pharmacists, Inc. makes no representations or warranties, express or implied, including, but not limited to, any implied warranty of merchantability and/or fitness for a particular purpose, with respect to the information, and specifically disclaims all such warranties. Readers of the information about the Janssen COVID-19 vaccine are advised that ASHP is not responsible for the continued currency of the information, for any errors or omissions, and/or for any consequences arising from the use of this information. Readers are advised that decisions regarding drug therapy are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and the information contained in this information is provided for informational purposes only. The American Society of Health-System Pharmacists, Inc. does not endorse or recommend the use of any drug. This information about the Janssen COVID-19 vaccine is not to be considered individual patient advice. Because of the changing nature of drug information, you are advised to consult with your physician or pharmacist about specific clinical use of any and all medications.

Other names

  • Adenoviral vector COVID-19 vaccine
  • Adenovirus 26 vector COVID-19 vaccine
  • Ad26.COV2.S
Last Revised - 03/05/2021