Someone at the CDC disagreed with the strategy of vaccinating people in long-term care facilities first because their weaker immune systems might not have an effective response to the vaccine. I'm not even sure if vaccinating front-line heathcare workers first makes sense because they've probably been exposed already (or not; this is easily checked with antibody tests).
You want to vaccinate people most likely to spread it. Who that is, I'm not sure.
So you'd want to give it first to people who are very likely to become severely ill themselves, and whose infection would cause others to become severely ill, directly or indirectly (eg through disease spread or through lost resources, as if an ER doc in an understaffed area became severely ill).
https://www.npr.org/2020/12/07/943945361/think-health-care-w...
> 42% of RNs in hospitals said they had ever been tested for the virus.
and anyways that's different from a one-time pre-vacccination test.
Not when your vaccine isn't proven to stop spread.