Johnson & Johnson said Tuesday that a large, global study showed its Covid-19 vaccine is more effective when given as a two-dose regimen, and that other data indicate the efficacy of the vaccine does not wane.
The two-dose regimen prevented 75% of moderate to severe Covid cases in all countries where it was tested — and 94% of such cases in the United States, where the vaccine probably had to grapple with fewer variants of the SARS-CoV-2 virus. Importantly, the two-dose regimen was 100% effective against severe disease.
It appears J&J may use the data to argue in favor of making a booster broadly available to people who received the one-dose vaccine six months ago or more. A press release from the company did not say so explicitly, but stated J&J had submitted the data to the Food and Drug Administration and plans to submit them to other regulators and the World Health Organization.