Janssen COVID-19 Vaccine: Uses, Side Effects, Dosage

What is COVID-19 vaccine, viral vector-Janssen, and what is it used for?

COVID-19 vaccine, viral vector-Janssen is a vaccine developed to protect against coronavirus disease (COVID-19) in adults. COVID-19 is an infectious disease caused by a type of coronavirus known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which resulted in a global pandemic that started in 2019. COVID-19, viral vector-Janssen vaccine stimulates the body’s immune system to fight against the SARS-CoV-2against SARS-CoV-2. The vaccine is administered as an intramuscular injection.

SARS-CoV-2 is a virus with a single strand of RNA as genetic material, and infection is spread through saliva droplets when an infected person talks, coughs, sneezes or laughs. SARS-CoV-2 has unique spike proteins on its surface membrane which help the virus attach to the angiotensin converting enzyme 2 (ACE2) receptors on human cells and penetrate the cells to initiate infection. The virus then uses the host’s cell machinery to grow, replicate and burst out of the cell to infect other cells.

COVID-19, viral vector-Janssen vaccine is produced by inserting the gene that produces the SARS-CoV-2 spike protein into human adenovirus type 26 (Ad26) vector, using DNA recombinant technology. The adenovirus is inactivated to prevent replication and to remove disease causing potential. The vaccine enters the cells and produces the SARS-CoV-2 spike protein which stimulates the immune system to produce antibodies that protect the vaccinated individual from developing COVID-19 disease if exposed to SARS-CoV-2.

COVID-19, viral vector-Janssen vaccine has not been approved by the FDA but was granted Emergency Use Authorization (EUA) in February 2021. In May 2022, the FDA restricted its use to adults who were clinically unable to receive other approved COVID-19 vaccines or those who chose to receive Janssen’s vaccine. In May 2023 Janssen Biotech, Inc. announced the expiry of the existing vaccine supplies and that they did not intend to update the vaccine to address emerging variants. On June 01, 2023, the FDA revoked the EUA and this vaccine is no longer available.

What are the side effects of the Janssen COVID-19 vaccine?

Common side effects of COVID-19 vaccine, viral vector-Janssen include:

Serious side effects of COVID-19 vaccine, viral vector-Janssen include:

• Hypersensitivity reactions including:
• Severe pain in the injected arm
• Generalized weakness
• Seizures

Less common side effects of COVID-19 vaccine, viral vector-Janssen include:

• Ringing in the ears (tinnitus)
• Diarrhea
• Vomiting
• Capillary leak syndrome
• Thrombosis with thrombocytopenia
• Immune thrombocytopenia
• Lymph node swelling (lymphadenopathy)
• Inflammation of the membrane around the heart (pericarditis)
• Inflammation of the heart muscle (myocarditis)
• Reduced skin sensation (hypoesthesia)
• Abnormal skin sensation (paresthesia)
• Facial paralysis (including Bell’s palsy)
• Fainting (syncope)
• Guillain-Barre syndrome, a condition in which the immune system attacks the nerves

Call your doctor immediately if you experience any of the following symptoms or serious side effects while using this drug:

• Serious heart symptoms include fast or pounding heartbeats, fluttering in your chest, shortness of breath, and sudden dizziness;
• Severe headache, confusion, slurred speech, severe weakness, vomiting, loss of coordination, feeling unsteady;
• Severe nervous system reaction with very stiff muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, and feeling like you might pass out; or
• Serious eye symptoms include blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights.

This is not a complete list of all side effects or adverse reactions that may occur from the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may also report side effects or health problems to the FDA at 1-800-FDA-1088.

What are the dosages of COVID-19 vaccine, viral vector-Janssen?

Injection, suspension

• 5x10¹⁰ virus particles/0.5 mL (5 doses per vial)

Adult:

COVID-19 Disease Prevention

• 0.5 mL intramuscular (IM) as a single dose

Booster dose

• Patients aged 18 years or older: 0.5 mL IM

Pediatric:

What drugs interact with the Janssen COVID-19 vaccine?

Inform your doctor of all medications you are currently taking, who can advise you on any possible drug interactions. Never begin taking, suddenly discontinue, or change the dosage of any medication without your doctor’s recommendation.

There are no data to assess interaction of COVID-19 vaccine, viral vector-Janssen with other vaccines or drugs.

The drug interactions listed above are not all of the possible interactions or adverse effects. For more information on drug interactions, visit the RxList Drug Interaction Checker.

It is important to always tell your doctor, pharmacist, or health care provider of all prescription and over-the-counter medications you use, as well as the dosage for each, and keep a list of the information. Check with your doctor or health care provider if you have any questions about the medication.

Pregnancy and breastfeeding

• Available data on COVID-19 vaccine, viral vector-Janssen use in pregnancy are insufficient to identify vaccine-associated risks to the fetus.
• There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to Janssen COVID-19 Vaccine during pregnancy. Women who are vaccinated with Janssen COVID-19 Vaccine during pregnancy are encouraged to enroll in the registry by visiting c-viper.pregistry.com.
• No information is available on the use of COVID-19 vaccine, viral vector-Janssen in breastfeeding women, or the vaccine’s effects on milk production or the breastfed infant.

What else should I know about COVID-19 vaccine, viral vector-Janssen?

• The Emergency Use Authorization for COVID-19 vaccine, viral vector-Janssen has been revoked and the vaccine is no longer available for use in the U.S.A.
• If you have received the COVID-19 viral vector-Janssen vaccine, seek immediate medical attention if you experience shortness of breath, chest pain, leg swelling, persistent abdominal pain, neurological symptoms such as severe or persistent headaches or blurred vision, or bruising beyond the vaccination site.