Question: I was just reading earlier this week that Moderna just applied for full FDA approval, and Pfizer applied last month.  How does full FDA approval differ from emergency use authorization?

Answer: FDA approval– through a process called Biologics License Application (BLA)– differs from FDA emergency use authorization (EUA) in several ways.  First, an EUA expires when the public health emergency ends, whereas a BLA has no such expiry.   Second, an EUA can be granted with less safety and efficacy data than a BLA.  In the case of Pfizer and Moderna, EUA applications included clinical trial data collected during the 3 month period after participants’ 2nd dose.  The BLA will include clinical trial data spanning a longer period (at least 6 months).  Third, approval of a BLA allows the pharmaceutical company the ability to market the vaccine in the US.  Fourth, BLA approval may provide increased legal standing for companies, schools, and other employers/venues to require COVID vaccination.  And finally, BLA approval may encourage more individuals who are in the “wait and see” category of vaccine acceptance to choose to get the vaccine as soon as possible.  For example, a recent Kaiser Family Foundation (KFF) survey found that 12% of US adults are in the “wait and see” category.  In its May survey, KFF found that among the various incentives discussed, “the one that appears to have the most resonance, particularly for those in the “wait and see” group, is full FDA approval of one or more of the COVID-19 vaccines. About a third (32%) of those who have not been vaccinated, including 44% of those who say they want to “wait and see,” say they would be more likely to get vaccinated if one of the vaccines currently authorized for emergency use received full approval from the FDA.” (Figure)

Figure: Vaccine Incentives (from KFF)