Risk Of Covid Hospitalization 5 Times Higher With Johnson & Johnson Shot Than Pfizer

Topline

Johnson & Johnson’s Covid-19 vaccine was far less effective at keeping people out of hospital than the Pfizer-BioNTech shot, according to a peer reviewed study published in JAMA Network Open Wednesday, bolstering the case for those vaccinated with a J&J shot to receive a second booster dose with an mRNA vaccine like Moderna and Pfizer.

J&J’s vaccine was less effective than Pfizer’s, a study found.

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Key Facts

The risk of being hospitalized with severe Covid-19 after vaccination was approximately five times higher in people who had received the J&J vaccine compared to the Pfizer-BioNTech shot, according to a study of around 1.4 million people ages 55 and over in France divided equally by vaccine type.

Pfizer’s shot was 92% effective at preventing hospitalization with severe Covid, compared to 59% for the J&J vaccine, the researchers found, “consistent with previous estimates” from smaller studies.

The researchers said they think the study is the largest to evaluate the effectiveness of the J&J vaccine in the general population to date and “included almost the entire population (of France) aged 55 years or older” who received the shot.

While every effort was taken to ensure no other factor could explain the difference—members of the two vaccine groups were matched for factors including age, sex, vaccination day and area of residence—the researchers said they “cannot completely exclude” another explanation, though they said using a vaccinated group made this less likely than if the shot’s cohort was compared to a group of unvaccinated people.

The findings bolster advice recommending J&J recipients have a second booster dose using an mRNA vaccine—the technology used in Moderna and Pfizer shots—the researchers said, which is already recommended in France and the U.S.

Key Background

In clinical trials, a single J&J shot was shown to be around 85% effective against severe Covid-19. In later studies in the general population, this figure dropped to around 68%. Compared to mRNA vaccines, the predominant shot used in the U.S. which were found to be around 90% effective in general population studies, J&J is effectively the worst performing vaccine in the country and the CDC recommends everyone get a booster shot of either Pfizer or Moderna shots. Though studies show the J&J vaccine is less effective than mRNA shots at preventing severe Covid and hospitalization, data overwhelmingly shows it is still more dangerous to be unvaccinated.

What We Don’t Know

Are people vaccinated with J&J fully protected? Guidance on vaccinations has shifted throughout the pandemic, often leaving the recipients of the least-used U.S. vaccine in flux as communications focused on more widely used Pfizer and Moderna vaccines. The CDC counts people who have completed the primary course of vaccination—one dose of J&J or two of Moderna and Pfizer—as “fully vaccinated.” Though the organization acknowledges the need for a single booster dose as protection wanes over time and recommends everybody get this, it has not changed the definition of “fully vaccinated” and said people will not be considered “up to date” without a booster. Though people who have had the J&J shot and another booster will be considered fully vaccinated and up to date, data still shows mRNA vaccines consistently offering higher levels of protection, making it unclear whether J&J recipients will need a third shot to “catch up” despite official guidelines. Use of the vaccine has dropped over the course of the pandemic in favor of mRNA shots, adding to the confusion. Official guidelines do not address the matter.

Big Number

17 million. That’s how many people have received the J&J vaccine in the U.S., according to CDC data. In comparison, more than 123 million have received two doses of Pfizer’s shot and more than 75 million two doses of Moderna’s.

Topline

Key Facts

Key Background

What We Don’t Know

Big Number

Further Reading