The Food and Drug Administration issued emergency use authorization Saturday to Johnson & Johnson to distribute its single-dose coronavirus vaccine. According to data reviewed by the agency, the jab from the pharmaceutical and consumer goods giant proved to be 66 percent effective at preventing COVID-19 infections in clinical trials against the virus, though less effective against the South African variant. It was also 85 percent effective at circumventing severe infection and offered “complete protection” from hospitalization death from COVID-19. While the pharmaceutical company is expected to start out small—with 20 million doses shipped by the end of March, and 100 million by the end of June—the vaccine is seen as easier to use and store than the Pfizer and Moderna vaccines, which required two doses and had to be frozen.

Dr. Anthony Fauci, senior medical advisor to President Joe Biden said Saturday that Americans should not decide against taking the J&J vaccine because they view its efficacy as inferior. The inoculation was still 100 percent effective at preventing death in trial participants who received it, as opposed to the placebo group.

“Don’t get caught up, necessarily, on the number game, because it’s a really good vaccine, and what we need is as many good vaccines as possible. Rather than parsing the difference between 94 and 72, accept the fact that now you have three highly effective vaccines. Period,” he said.

The approval of the third vaccine comes just days after the nation hit the gut-wrenching death toll of 500,000 people. It also comes as experts warn that a recent decline in COVID cases could lead to a false sense of security and premature easing of restrictions at a time when newly emerging variants of the virus pose further risk. With that in mind, the Johnson & Johnson vaccine is seen as a crucial way to bolster defenses at a critical moment. “This one dose regimen offers important logistical and practical advantages for mass vaccination campaigns. It can lead to the ability to reach both individual and herd immunity more quickly,” said Gregory Poland, director of the Mayo Clinic’s vaccine research group and a paid consultant for Johnson & Johnson who presented on the vaccine to the FDA. “Essentially, it simplifies the process. People only have to make one appointment for their complete vaccination.”