WASHINGTON (AP) Documents released by U.S. regulators Tuesday confirmed that Pfizer and BioNTechs COVID-19 vaccine was strongly protective against COVID-19 offering the worlds first detailed look at the evidence behind the shots.

The Food and Drug Administration posted its analysis online even as across the Atlantic, Britain on Tuesday began vaccinating its oldest citizens with the Pfizer-BioNTech shots.

But the U.S. judges experimental vaccines in a unique way: On Thursday, the FDA will convene whats essentially a science court that will debate in public and live-streamed just how strong the data backing the shots really is.

A panel of independent scientists will pick apart the FDAs first-pass review before recommending whether the vaccine appears safe and effective enough for millions of Americans. The FDA, which typically follows the committees advice, is expected to issue a decision in the days following the review. If given the green light, the first recipients would be health care workers and nursing home residents according to plans laid out by each state.

Pfizer and its German partner BioNTech previously reported the shots appear 95% effective at preventing mild to severe COVID-19 disease in a large, ongoing study. Thats based on the first 170 infections detected. Only eight of the infections were among volunteers given the real vaccine while the rest had received a dummy shot.