J&J reports second dose of COVID-19 vaccine boosts protection to 94%
A second dose of Johnson & Johnson’s COVID-19 vaccine given 2 months after the initial shot boosted protection to 94% among people enrolled in a phase 3 trial in the United States, the company said Tuesday.
Compared with the two-dose messenger RNA vaccines from Pfizer-BioNTech and Moderna, Johnson & Johnson’s single-shot vaccine has demonstrated lower efficacy against SARS-CoV-2. The newly reported efficacy of two doses of the vaccine given 56 days apart would be on par with the peak efficacy of the other two vaccines.
Additionally, Johnson & Johnson reported that the two-dose regimen provided 100% protection against severe or critical COVID-19 after at least 14 days (95% CI, 33%-100%), and 75% protection against symptomatic COVID-19 in a global cohort (95% CI, 55%-87%).
The data are from the phase 3 ENSEMBLE 2 study — a randomized, double-blind, placebo-controlled clinical trial. In the U.S. arm of the trial, there was one recorded case of COVID-19 in the vaccine arm compared with 14 in the placebo arm.
Given at 2 months, the booster dose increased antibody levels by four or six times, Johnson & Johnson said. When a booster was given at 6 months, antibody levels increased ninefold in 1 week and 12-fold after 4 weeks, it said.
In addition, real-world data shared by the company from a cohort of 390,000 people who received one shot between March and July demonstrated a vaccine effectiveness of 79% (95% CI, 77%-80%) against SARS-CoV-2 infection and 81% (95% CI, 79%-84%) against COVID-19-related hospitalization when compared with more than 1.5 million unvaccinated people. Johnson & Johnson reported that there was “no evidence of reduced effectiveness over the study duration, including when the delta variant became dominant in the U.S.”
“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,” Paul Stoffels, MD, vice chairman of the executive committee and chief scientific officer at Johnson & Johnson, said in a press release. “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.”
Johnson & Johnson, which indicated last month that it would seek authorization of a booster shot for its vaccine, said Tuesday that it has now submitted the available data to the FDA.
The debate about offering booster shots in the U.S. has been ongoing for weeks and faces another potential important vote this week when the CDC’s advisory committee for immunizations meets to consider recommendations.