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Johnson & Johnson COVID-19 Vaccine

Published on Apr 26, 2021 and last reviewed on May 16, 2022   -  6 min read


The COVID-19 pandemic reminds us of the importance of immunization, to save millions of lives. One such critical tool for fighting this global pandemic is the approved Johnson & Johnson COVID-19 vaccine, To know more, have a look at this article.

Johnson & Johnson COVID-19 Vaccine


Johnson & Johnson COVID-19 vaccine is a single dose vaccine developed by the Janssen Pharmaceutical Companies of Johnson & Johnson to prevent COVID-19. It is the third COVID-19 vaccine that got approved after the two-shot regimens of Pfizer-BioNTech and AstraZeneca. It is the first single-dose vaccine. However, people ages 18 years and older who are moderately or severely immunocompromised and received Johnson & Johnson’s Janssen COVID-19 vaccine (single shot) should get a second dose of an mRNA COVID-19 vaccine (Pfizer-BioNTech or Moderna).

Why Johnson & Johnson COVID-19 Vaccine?

The data from the Phase 3 ENSEMBLE study shows that this vaccine is 85 % effective in preventing COVID-19. It provides protection 28 days after the vaccination. The Johnson & Johnson company is planning to apply for the Biologics License Application with the FDA. It uses the AdVac vaccine platform, a unique technology that was used to develop Janssen’s European Commission-approved Ebola vaccine.

What Is the Phase 3 ENSEMBLE Study?

The study was enabled to understand the safety and efficacy of this COVID-19 vaccine in protecting against both moderate and severe cases. The efficacy was evaluated on day 14 and day 28 after vaccination. This clinical trial was conducted in about eight countries. About 34 % of people who participated in the trial were above the age of 60, and 41 % of individuals had comorbidities. After 14 days of vaccination, the trial results showed that it is 66.9 % effective in moderate cases and 76.7% effective in severe cases. The efficacy was around 66.1 % in moderate cases and 85.4 % in severe cases when the results were taken at least 28 days after getting the vaccine.

How Is the Vaccine Stored?

The Johnson & Johnson vaccine is compatible with standard vaccine storage and distribution channels with easy delivery to remote areas. The vaccine remains stable for two years at -4 degrees F (-20 degrees Celsius) and a maximum of three months at temperatures of 36 to 46 degrees F (2 to 8 degrees Celsius). The vaccine should not be re-frozen if distributed at a temperature of 36 - 46 degrees F (2 to 8 degrees Celsius).

What Age Group Can Have This Vaccine?

Johnson & Johnson COVID-19 vaccine is recommended for individuals of age 18 years and above. This vaccine is reliable and effective in people with associated comorbidities like diabetes, hypertension, cardiac diseases, and lung diseases. In people with these medical conditions, the risk of progression of the disease to severe form is increased. It can also be given to people who previously had a COVID-19 infection. Breastfeeding women are safe to get this vaccine, and discontinuation after vaccination is also not needed.

Who Should Not Get the Vaccine?

How Is the Vaccine Given?

Johnson & Johnson vaccine is a single-dose vaccine. It is administered intramuscularly in the deltoid muscle.

What Is the Recommended Dose of the Johnson & Johnson Vaccine?

0.5 ml of the vaccine is given as a single dose intramuscularly. You should wait for 14 days before taking a vaccine for any other health conditions.

What Should You Mention Before Getting Vaccinated?

Before getting vaccinated, you have to inform if you:

How Is Johnson & Johnson Vaccine When Compared to the Other Two Vaccines?

Pfizer and Moderna require two shots to give the maximum protection against the COVID-19. But in the case of the Johnson & Johnson vaccine, it is a single-shot vaccine. If you are worried about the side effects, you should go for the Johnson & Johnson vaccine, as the side effects are minimal compared to Pfizer and Moderna vaccines. According to Pfizer, about 3.8 % of their clinical trial participants experienced fatigue and 2 % experienced headaches. According to Moderna, 9.7 % of the trial participants experienced fatigue and headache. According to the Center for Disease Control and Prevention, the side effects from the second shot will be more than the first shot.

In trials of both Pfizer and Moderna, more people experienced side effects after the second shot. You are bound to get the second shot even if you experience side effects from the first shot. The main side effects of the Johnson & Johnson vaccine are pain at the injection site and flu-like symptoms.

Other Than the Side Effects, How Are Pfizer and Moderna Different From the Johnson & Johnson Vaccine?

In Pfizer and Moderna vaccines, mRNA is introduced into your body, unlike the traditional vaccines where a weakened or inactivated germ is injected into the body. The mRNA is a code that serves as an instruction manual to the immune system to identify the virus and attack it. In the case of the Johnson & Johnson vaccine, instead of using mRNA, it uses a disabled adenovirus to provide instructions on how to attack the virus.

Are There Benefits From the Technology Used in Johnson & Johnson Vaccine?

Yes, the biggest advantage is that Johnson & Johnson COVID-19 vaccine can be kept at refrigerator temperatures for months, and it will be stable. In contrast, Pfizer and Moderna vaccines are not as durable as Johnson & Johnson vaccines, and they require very cold storage temperatures. Once Pfizer and Moderna are taken out of cold temperatures, their window time is short, but it is not the case in Johnson & Johnson vaccine. Hence it is better to maintain and deliver to different parts of the country, especially rural areas.

What Are the Side Effects of the Johnson & Johnson Vaccine?

The side effects that have been reported include :

There can be general side effects like other vaccines which includes:

There is also a report saying that there can be severe allergic reactions.

What Can Be the Signs of a Severe Allergic Reaction?

The signs of a severe allergic reaction include:

These signs are not the usual side effects. But when there is a serious allergic reaction, these unexpected side effects may occur.

How Effective Is Johnson & Johnson COVID-19 Vaccine?

Is the Johnson & Johnson Vaccine Effective Against the New Variants of Coronavirus?

Clinical trials have proved the Johnson & Johnson vaccine to be efficient against the new variants of coronavirus, like the beta (B1.351), zeta (P.2), Omicron (BA.1, BA.1.1, and BA.2), and Delta (B.1.617.2) variants.

Is Booster Dose of Johnson & Johnson Vaccine Recommended?

As of October 20, 2021, the United States FDA has approved the use of booster dose of the Johnson & Johnson vaccine. People of 18 years and above should get a booster dose It is recommended in people who have taken the single-dose shot of the J&J vaccine before two months or in individuals who have taken any other approved or authorized vaccine. The booster dose has the same formulation and dosage as that of the primary dose. Some people can also choose to receive a second booster. On March 29th, 2022, the CDC recommended that a second booster dose (with any mRNA vaccine) can be administered after four months of the initial booster dose.

Why Was the Johnson & Johnson COVID-19 Vaccine Temporarily Stopped?

The Federal Health Authorities recommended temporarily stopping the Johnson & Johnson vaccine while investigating a potential link to very rare blood clots. CDC and FDA are reviewing the six reported cases of rare and severe types of blood clots that developed after getting vaccinated. Hence there was a temporary pause in administering the vaccine. After reviewing the available data, the CDC and FDA resumed the use of the Johnson & Johnson vaccine in the United States from April 23, 2021. It was attributed that the benefits of getting the vaccine outweigh the potential risks that can happen with vaccination, thus resuming the use of the J&J vaccine. Nevertheless, women above the age of 50 with reduced platelets should be cautious of getting the vaccine as it risks blood clot formation. In such cases, an alternative vaccine may be chosen.


No vaccine can be 100 % effective. The only thing is that it reduces the severity of the disease. That is the most important factor of a vaccine. Everyone must get a booster dose after the primary vaccination. Johnson & Johnson COVID-19 booster dose increased vaccine effectiveness (VE) against hospitalization and death to 85 %. Even if it is not 100 % effective, there are less chances of getting any severe complications. Getting vaccinated is the most important thing that can be done for self-protection against COVID-19, help end the pandemic and stop new variants emerging.

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Last reviewed at:
16 May 2022  -  6 min read




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