U.S.-based pharmaceutical company Johnson & Johnson said Tuesday new “real world” and phase 3 study data show a second shot of its single-dose vaccine about two months after the initial shot increased its effectiveness to 94%.
In a news release on its website, the company said its clinical trial in the United States showed the booster shot also provided as much as 100 percent protection against severe or critical COVID-19 symptoms beginning at least 14 days after final vaccination.
The company also said there was no evidence of reduced effectiveness over the study duration, including when the delta variant became dominant in the U.S.
They said tests performed outside the U.S. showed it provided up to 87% protection against severe or critical COVID-19. The company also said a booster given six months after the initial dose saw antibody levels increase by nine times one week after the booster and continued to climb as high as 12-fold.
On Friday, an FDA advisory committee voted to recommend emergency authorization of additional Pfizer shots for Americans 65 and older and those at high risk of severe illness, but voted to recommend against broader approval, saying it wants to see more data.
J&J said it has submitted data to the FDA and plans to submit it to other regulators, the World Health Organization and other vaccine advisory groups worldwide to inform their decision-making.
Some information in this report came from the Associated Press and the Reuters.