The Johnson & Johnson COVID-19 vaccine is more effective when administered as a two-dose regimen, suggest data released by the company on Tuesday.

A second dose of the vaccine administered 56 days following the first dose yielded 75% protection against symptomatic illness in a global clinical trial. The protection increased to 94% in the United States. While the reason for this difference was not clear from the company′s statement, it could be tied to lesser number of variants in the US when the data were collected.

Giving a second dose of the vaccine two months after the first dose increased the antibody levels four- to six-fold higher than that observed following the single dose… (NDTV – AFP, September 22, 2021)