FDA director: The agency expects to approve Pfizer's vaccine after today's crucial hearing

• An expert panel is meeting today to advise the FDA on whether to approve or deny Pfizer's coronavirus vaccine for emergency use.
• Before it began, FDA Commissioner Stephen Hahn told NBC's Savannah Guthrie the vaccine already meets the agency criteria for approval, but that it will still take into account what the panel recommends.
• After the panel's vote, Hahn said, the FDA plans to "act quickly."
• Follow Business Insider's live blog of the hearing today.

A panel of independent experts is meeting today to evaluate Pfizer's coronavirus vaccine. By day's end, they're expected to come to a vote that will advise the US Food and Drug Administration (FDA) to approve or deny the shot for emergency use.

But FDA Commissioner Dr. Stephen Hahn said the outcome is already predictable, and that the agency intends to act on the advisory panel's advice immediately.

"We'll have to see what the scientific and medical discussion is today. But our plan is to take their recommendations into account for our decision making and make a decision shortly thereafter ... We intend to act quickly," he told Savannah Guthrie live on NBC News' TODAY before the advisory committee convened.

The head of the FDA assured, "our initial assessment is that this is a vaccine that does meet our criteria … But we do want to hear from the vaccine advisory committee."

If indeed approved, high-priority Americans, including nursing home residents and healthcare workers, are expected to begin getting the vaccine in the next couple days.

Pfizer's vaccine has been shown to be safe and 95% effective at preventing symptomatic COVID-19. But the advisory committee will likely discuss the pros and cons of approving a vaccine that still has a lot of unknowns, like whether it protects against asymptomatic infection and "silent spreading," how long its protection against COVID-19 lasts, and whether there's enough data on older Americans to justify injecting some of them first.

Follow Business Insider's live blog of the hearing here.