Pfizer's COVID-19 vaccine faces one final hurdle as it races to become the first shot green lighted in the US: a panel of experts who will scrutinize the company's data for any red flags.

Thursday's meeting of the Food and Drug Administration's vaccine advisory panel is likely the last step before a US decision to begin shipping millions of doses of the shot, which has shown strong protection against the coronavirus. The FDA is expected to follow the committee's advice, although it is not required to do so.