The Johnson & Johnson Covid vaccine is more effective when given as a two-dose regime, according to new data released by the company on Tuesday. xA second shot given 56 days after the first provided 75 percent protection against symptomatic Covid in a global clinical trial, with that level rising to 94 percent in the United States. When a second shot was given two months after the first, antibody levels rose to four to six times higher than observed after the single dose. Overall, the data is positive news for the almost 15 million Americans who received one dose of the J&J vaccine but have been left in the dark about if and when they might need a booster. In a separate study of 390,000 US people who received the J&J vaccine from March to July 2021, efficacy of a single J&J shot was 79 percent against infection and 81 percent against hospitalization.

Source: The Guardian September 21, 2021 15:00 UTC