FDA backs Johnson & Johnson COVID-19 vaccine as safe and effective

The Food and Drug Administration backed Johnson & Johnson’s single-dose coronavirus vaccine as safe and effective on Wednesday as the agency weighs whether to clear the shot for emergency use.

FDA staff affirmed J&J’s finding that the vaccine was 66 percent effective overall at warding off moderate and severe COVID-19 cases and 85 percent effective at preventing the most serious infections.

While not as strong as Pfizer and Moderna’s two-dose vaccines, that efficacy rate could still make J&J’s shot a helpful weapon in the battle against the pandemic. It’s also...