Johnson & Johnson's one-shot Covid-19 vaccine effective, safe: FDA staff

J&J's vaccine was 66% effective in preventing Covid-19 against multiple variants in a global trial involving nearly 44,000 people, the company said last month. Its effectiveness varied from 72% in the United States to 66% in Latin America and 57% in South Africa, where a new variant has spread, though the vaccine was 85% effective overall in stopping severe cases of the disease.