Johnson &Johnson’s Janssen COVID-19 Vaccine Overview
and Safety

General Information
Name: JNJ-78436735
Manufacturer: Janssen Pharmaceuticals Companies of
Johnson &Johnson
Type of Vaccine: Viral Vector
Number of Shots: 1 shot
Booster Shots: At this time, people who got the J&J/Janssen
vaccine are not eligible for a booster shot. More data on the
effectiveness and safety of J&J/Janssen booster shots are
expected soon. With those data in hand, CDC will keep the
public informed with a timely plan for J&J/Janssen booster
How Given: Shot in the muscle of the upper arm
Does NOT Contain: Eggs, preservatives, latex, metals
Full List of Ingredients

Who Should Get Vaccinated
How Given: Shot in the muscle of the upper arm
Does NOT Contain: Eggs, preservatives, latex, metals
Full List of Ingredients
• The J&J/Janssen COVID-19 Vaccine is recommended for people 18 years and older.
• Learn more about how CDC is making COVID-19 vaccine recommendations.

Who Should NOT Get Vaccinated
• If you have had a severe allergic reaction (anaphylaxls) or an Immediate allergic reaction, even if it was not severe,
to any ingredient in the J&j/Janssen COVID-19 Vaccine (such as polysorbate), you should not get the J&J/Janssen
COVID-19 Vaccine.
• A severe allergic reaction is one that needs to be treated with epinephrine or EpiPen or with medical care. Learn
about common side effects of COVID-19 vaccines and when to call a doctor.
• An immediate allergic reaction means a reaction within 4 hours of exposure, including symptoms such as hives,
swelling, or wheezing (respiratory distress).
If you aren’t able to get the J&j/Janssen COVID-19 Vaccine, you may still be able to get a different type of COVID-19
vaccine. Get more information for people with allergies.

Possible Side Effects

In the arm where you got the shot: Throughout the rest of your body

• Pain
• Redness
• Swelling

These side effects happen within a day or two of getting the vaccine. They are normal signs that your body is building
protection and should go away within a few days.

Throughout the rest of your body

• Tiredness
• Headache
• Muscle pain
• Chills
• Fever
• Nausea

Fainting After Vaccination

Fainting (syncope) and other events that may be related to anxiety like rapid breathing, low blood pressure, numbness, or
tingling can happen after getting any vaccine. Although uncommon, these events are not unexpected, and they are generally
not serious.
According to information from the Vaccine Adverse Event Reporting System (VAERS), there were 653 reports of fainting events
(fainting and near-fainting) among nearly 8 million doses of J&J/Janssen COVID-19 Vaccine administered in the United States in
March and April 2021. This translates to a rate of about 8 fainting events for every 100,000 doses of the J&J/Janssen COVID-19
Vaccine given. These events occurred during the recommended 15-minute wait after vaccination. It’s not clear at this time
whether these events were associated with the vaccine or with anxiety, possibly related to preexisting concerns some people
who chose to get the one-dose J&J/Janssen COVID-19 Vaccine may have about needles or shots.

By comparison, the rate of fainting after flu vaccination in 2019-2020 was 0.05 per 100,000 doses.
Learn more about possible side effects after getting a COVID-19 vaccin

Other Authorized and Recommended COVID-19 Vaccines in the United States
• Pfizer-BioNTech
• Moderna

You should get a COVID-19 vaccination as soon as possible. Do not wait for a specific brand. Ail currently authorized and
recommended COVID-19 vaccines are safe and effective, and CDC does not recommend one vaccine over another.

Safety Data Summary

• In clinical trials, side effects were common within 7 days of getting vaccinated and were mostly mild. Some people had
side effects that affected their ability to do daily activities.
• Side effects were more common in people 18-59 years old compared to people 60 years and older.
• There is a plausible causal relationship between J&J/Janssen COVID-19 Vaccine and a rare and serious adverse eventblood clots with low platelets (thrombosis with thrombocytopenia syndrome, or ITS).
– It occurs at a rate of about 7 per 1 million vaccinated women between 18 and 49 years old.
– For women 50 years and older and men of all ages, this adverse event is even more rare.
• Find the latest updates on J&J/Janssen COVID-19 Vaccine and blood clots with low platelets.
• CDC will continue to provide updates as we learn more about the safety of the J&J/Janssen COVID-19 Vaccine in realworld conditions.

Learn more about vaccine safety monitoring after a vaccine is authorized or approved for use.

How Well the Vaccine Works

• The J&J/Janssen COVID-19 Vaccine was 66.3% effective in clinical trials (efficacy) at preventing laboratory-confirmed
COVID-19 infection in people who received the vaccine and had no evidence of being previously infected. People had the
most protection 2 weeks after getting vaccinated.
• In the clinical trials, the vaccine had high efficacy at preventing hospitalization and death in people who did get sick. No
one who got COVID-19 at least 4 weeks after receiving the J&J/Janssen COVID-19 Vaccine had to be hospitalized.
• CDC will continue to provide updates as we learn more about how well the J&J/Janssen COVID-19 Vaccine works in realworld conditions.

Clinical Trial Demographic Information

Clinical trials for the J&J/Janssen COVID-19 Vaccine included people from the following racial, ethnic, age, and sex categories

• 62% White
• 17% Black or African American
• 8% American Indian or Alaska Native
• 5% multiple races
• 4%Asian
• 0.3% Native Hawaiian or Other Pacific Islander

• 45% Hispanic or Latino
/ • 52% not Hispanic or Latino
• 3% unknown

• 56% male
• 45% female
• <0.1 % undifferentiated or unknown sex
Age breakdown:
• 67% 18-59 years
• 34% 60 years and older
– 20% 65 years and older
– 4% 75 years and older

Forty (40.8%) of people who participated in the clinical trials had at least one condition that put them at risk of severe illness
from COVID-19. The most frequent underlying medical conditions among participants were obesity (28.7%), high blood
pressure (10.2%), type 2 diabetes (7.3%), and HIV infection (2.7%).

Related Pages
> Possible Side Effects
>Safety of COVID-19 Vaccines
> Benefits of Getting Vaccinated
> How Vaccines Work
> Viral Vector Vaccines

O For Healthcare Workers
Johnson &Johnson’s Janssen COVID-19 Vaccine: General information, schedule, and administration overview