The Food and Drug Administration is expected to grant full approval to Pfizer-BioNTech’s coronavirus vaccine in the coming days, according to four people with knowledge of the plans.

If approved, the vaccine would be the first in the United States to receive full licensure, and it could result in private businesses issuing a new wave of vaccine mandates.

Public health experts have argued that the FDA’s move to grant full approval will be a pivotal moment in the fight against the pandemic, predicting that it would ease the ability of employers to mandate that millions of holdout Americans get vaccinated.

Here’s what to know: