If more people had been vaccinated, fewer people would've been ill and fewer of those who were ill would've required hospitalization. So chances are he doesn't come out of retirement to help, because there isn't a crisis due to a shortage of health care providers - which results in him being in close contact with COVID carriers.
It's dishonest to not recognize that unvaccinated people contributed to the circumstances here. The degree to which they contributed, you might debate. But they definitely contributed.