. A COVID vaccine from Johnson & Johnson was endorsed as safe and effective by the FDA, the White House is going to start shipping masks to health centers and food pantries, and Biden's health secretary nominee faced a second day of Senate grilling. ADVERTISEMENT We'll start with J&J: The hopeful vaccine news keeps coming: Johnson & Johnson's single-dose COVID-19 vaccine effective and safe, per FDA analysis Johnson & Johnson's single-dose coronavirus vaccine is effective at preventing moderate and severe cases of COVID-19, according to an analysis of the trial data published by the Food and Drug Administration on Wednesday. The company's single dose vaccine is 66 percent effective, well within the agency's standards. The vaccine is also safe to use, according to the analysis.