How full FDA approval would impact COVID-19 vaccine mandates, competition In depth: The impact of full FDA approval By: KGTV Staff and last updated 2021-04-12 11:37:30-04 Pfizer could apply for full FDA approval of its COVID-19 vaccine as early as this month, and Moderna could follow soon after. If regulators sign off, that status change would have significant impacts on vaccine mandates in workplaces and other experimental vaccine candidates still in development. Currently, the three vaccines on the market only have an Emergency Use Authorization (EUA), meaning they are âauthorizedâ by the Food and Drug Administration but not âapproved.â