Currently there are several competing companies that are trying to develop a vaccine for SAR-Cov-2. As each company has said that they are going to engage in at-risk-production if they think that they have a "winner" (begin mass production before clinical trials are completed and before FDA approval), what happens if the (completed) clinical trials show only slight differences in safety and efficacy. Would the FDA approve both vaccines? Has anything like this happened before?
My attempts to research this only seem to lead to the FDA approval process, not whether the FDA has or would approve different vaccines for the same patient group.
(I'm predicating FDA approval for general population use - not an approval for specific individuals or groups).