Johnson & Johnson is on track to roll out its single-shot coronavirus vaccine in March, and plans to have clear data on how effective it is by the end of this month or early February, the US healthcare company's chief science officer said. Dr Paul Stoffels in an interview on January 12 also said J&J expects to meet its stated target of delivering 1 billion doses of its vaccine by the end of this year as the company ramps up production. The New York Times reported earlier on January 13 that J&J was experiencing manufacturing delays that would reduce the number of doses initially available. “We are aiming for 1 billion doses in 2021. If it is a single dose, that means 1 billion people,” Said Stoffels. Watch the video to know more.