NEW BRUNSWICK, NEW JERSEY — Johnson & Johnson announced on Jan. 29 that its single-dose coronavirus vaccine was 66 percent effective in preventing moderate disease 28 days after injection in its Phase 3 global trials, according to a company press release.

The company said the vaccine was 85 percent effective at preventing severe COVID, and that no one had died or was hospitalized 28 days following their vaccination.

Like the AstraZeneca-Oxford vaccine and Russia's Sputnik V vaccine, and unlike Pfizer and Moderna's mRNA vaccines, Johnson & Johnson's vaccine uses a modified adenovirus as a vector.