Hopefully they're careful with vaccines. There are people who don't like being told what to do and will ignore the government out of spite (mostly rural Republicans and libertarians). Doubling down on telling people they have to get vaccinated won't work for the same reason. Not that this is telling people what to do; you just have to be careful with policy so it doesn't backfire.

Biden appointing Fauci as his chief medical advisor was a mistake because Fauci has been politicized. Democrats will get the shot regardless, so finding a new face would have sent a signal to Republicans.