Booster Recommendations After J&J's Janssen COVID-19 Vaccine

J&J booster is available, but in limited situations. Health experts recommend Pfizer-BioNTech or Moderna booster instead.

By December 2022, nearly 19 million people in the United States had received Johnson & Johnson's Janssen COVID-19 vaccine (the J&J vaccine), a single-dose vaccine, according to the Centers for Disease Control and Prevention (CDC).

Three other COVID-19 vaccines have been approved in the U.S.: an mRNA vaccine from Pfizer-BioNTech, an mRNA vaccine from Moderna, and a protein subunit vaccine from Novavax. If you get one of these three, you need two jabs to be considered fully vaccinated with your primary series.

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Design by Jo Imperio

Boosters are recommended to help maintain immunity and to stave off emerging strains of the coronavirus. For example, the Delta variant accounted for 83% of sequenced cases in the U.S. at one point, per CDC data. That variant and others that followed weren't around when the vaccines were first developed. As other strains have emerged, experts have raised concerns about how protective early forms of the vaccine could be.

In the U.S., public health officials have recommended booster shots for people who have had initial vaccination with Pfizer-BioNTech, Moderna, J&J, and Novavax. The boosters recommended in the U.S. are the Pfizer-BioNTech and Moderna mRNA vaccines, according to the CDC. However, if you are unable to receive an mRNA vaccine, you can get a Novavax or J&J booster.

What Is the J&J Vaccine?

The J&J vaccine uses a viral vector to deliver genetic material, according to the CDC. A vector is a delivery system. In this case, a virus is the delivery system for material that provides immunity against SARS-CoV-2, the virus that causes COVID-19.

The virus in the J&J vaccine is modified in a way that makes it harmless. And it's also modified with a gene that codes for certain harmless portions of the SARS-CoV-2 virus. That triggers the body's immune system to be able to recognize and fight SARS-CoV-2 if you encounter it later.

According to the CDC, the Pfizer-BioNTech and Moderna vaccines are recommended over the J&J vaccine. The strongest reason for this is the vaccine's side effects. It also happens to be a monovalent vaccine.

Monovalent means that the vaccine protects against only the original virus that causes COVID-19. Unlike monovalent vaccines, bivalent vaccines protect against both the original virus and Omicron variants. And the CDC recommends that you get one of the two bivalent vaccines: either Pfizer-BioNTech or Moderna.

However, the CDC says that, while it has some drawbacks, the J&J vaccine could be an alternative for people who have had an adverse reaction to one of the other vaccines or who don't have access to the other vaccines.

J&J Vaccine Protection

The COVID-19 vaccines cleared for use in the U.S. were designed to protect against the original virus. But viruses have a knack for mutating, and SARS-CoV-2 is no different. The CDC monitors variants circulating in the U.S.

While there's good evidence that the two-dose mRNA vaccines are effective against new variants, less is known about the J&J one-dose vaccine.

A small study published in 2022 in Frontiers in Immunology found that J&J's one-dose vaccine falls short. The research was based on blood samples from 17 people immunized with two doses of an mRNA vaccine and 10 people with one dose of J&J. The researchers found that J&J's vaccine was not as effective and showed a bigger drop against the Delta and Lambda variants.

"The message that we wanted to give was not that people shouldn't get the J&J vaccine, but we hope that in the future it will be boosted with either another dose of J&J or a boost with Pfizer or Moderna," study author Nathaniel Landau PhD, a virologist at New York University's Grossman School of Medicine, told The New York Times.

The findings counter other data suggesting that the single-dose vaccine generates a strong and persistent antibody response against the Delta variant. In a news release issued in July 2021, J&J cited data from a pair of small studies demonstrating the single shot's durable protection against multiple variants.

Boosters After the J&J Vaccine

If you received the J&J vaccine as your primary series, the CDC recommends a bivalent booster next. The two bivalent boosters are the Pfizer-BioNTech and Moderna vaccine.

Bivalent boosters initially became available for people 12 years and older in September 2022. In October, they were available for children between 5 and 11 years as well. And in December 2022, the CDC said children ages 6 months to 5 years were eligible for a bivalent booster.

However, the CDC says there are some situations in which you can opt out of the bivalent booster:

  • You had a severe reaction to an mRNA vaccine (Pfizer-BioNTech or Moderna).
  • You are severely allergic to an ingredient in the Pfizer-BioNTech or Moderna vaccines.
  • You want to get the J&J vaccine anyway even though it may cause more side effects.
  • You are at least 18 years old.

The Novavax booster is also an option if you are unable or unwilling to get the Pfizer-BioNTech or Moderna vaccine. The Novavax booster is also a monovalent vaccine, meaning it protects against only the original variant of the virus.

The CDC is not alone in its mix-and-match approach. The World Health Organization (WHO) also recommends that people who initially were vaccinated with the J&J vaccine receive another brand's booster.

A Quick Review

Amid the chatter about boosters, public health advocates and clinicians continue to drum home the importance of getting vaccinated in the first place. The more people who are vaccinated, the less chance the virus has of spreading. And that keeps everyone protected.

If you were first vaccinated with the J&J vaccine, the CDC recommends getting a bivalent booster next. That's because the bivalent boosters—Pfizer-BioNTech and Moderna—protect against both the original variant of SARS-CoV-2 and Omicron variants. (Monovalent vaccines protect against only the original virus the causes COVID-19.)

If you can't receive a bivalent booster, you can get a monovalent booster instead. If you have questions or want to explore your options, talk to a healthcare provider for advice.

The information in this story is accurate as of press time. However, as the situation surrounding COVID-19 continues to evolve, it's possible that some data have changed since publication. While Health is trying to keep our stories as up-to-date as possible, we also encourage readers to stay informed on news and recommendations for their own communities by using the CDC, WHO, and their local public health department as resources.

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