A booster of the single-dose Johnson & Johnson coronavirus vaccine two months after receipt of the first shot offers 94% protection against moderate to severe COVID-19 in the U.S., the company announced Tuesday.
The booster also offers 100% protection against severe/critical COVID-19 at least two weeks after receiving the second dose, according to results from an ongoing clinical trial.
Put another way, antibody levels rose four to six times higher following a booster shot given two months after the first dose of the J&J COVID-19 vaccine. And when given six months after the first dose, the booster led to a 12-fold increase in antibody levels after about a month.
The company said the safety of the vaccine “remained consistent and was generally well-tolerated when administered as a booster.” It plans on sending its data to the U.S. Food and Drug Administration and other regulatory agencies “to inform decision-making on local vaccine administration strategies.”
“It is critical to prioritize protecting as many people as possible against hospitalization and death given the continued spread of COVID-19. A single-shot COVID-19 vaccine that is easy to use, distribute and administer, and that provides strong and long-lasting protection is crucial to vaccinating the global population,” Dr. Paul Stoffels, vice chairman of the executive committee and chief scientific officer at Johnson & Johnson, said in a statement. “At the same time, we now have generated evidence that a booster shot further increases protection against COVID-19 and is expected to extend the duration of protection significantly.”
Real-world evidence outside clinical trials also showed that just one dose of the J&J vaccine was 79% effective against coronavirus infection and 81% effective against COVID-19-related hospitalization.
This protection did not wane over the study’s duration, even when the highly contagious delta variant dominated the U.S., the company said. Real-world data included more than 390,000 people who received the J&J vaccine and more than 1.52 million unvaccinated people.
The J&J COVID-19 vaccine has been mostly left out of the booster shot conversation until now. Part of the reason is that the shot received its emergency use authorization about two months after the Pfizer-BioNTech and Moderna coronavirus vaccines did.
The Pfizer vaccine recently received FDA approval; the Moderna vaccine is expected to be considered for approval soon. It’s unclear what step of the process the J&J vaccine is in.
It’s also unclear when and if J&J booster shots will be authorized for use in the U.S.
An FDA advisory committee voted in favor of Pfizer booster shots for people ages 65 and older and those at severe risk of COVID-19 last week. The FDA still has to officially authorize the third doses. A Centers for Disease Control and Prevention advisory panel is scheduled to meet this week to discuss Pfizer booster shots.
More than 181.7 million Americans are fully vaccinated as of Sept. 20, a CDC tracker shows. That includes 14.6 million people who have received the J&J vaccine.