Today, Johnson & Johnson (J&J) announced that a second dose of its COVID-19 vaccine given 2 months after the first raises its effectiveness against moderate to severe disease from 70% to 94% in the United States.
The booster was also well tolerated, generating side effects similar to those observed after the first dose.Promising data, but some experts want moreIn a press release, the company said that its phase 3 US clinical trial data showed that a booster dose given at 56 days conferred 94% protection against moderate to severe disease in nearly 30,000 adult participants.
The confidence interval (CI), however, was wide, at 58% to 100%, leaving doubt as to the precision of the finding.J&J also said that antibody levels quadrupled when a