1) as you said they seem to be, as a group, vaccine adverse. Maybe because they see themselves as the ones that 'should be giving the orders not taking them'
2) Similarly, perhaps in macho alignment with point 1, their masking discipline was poor
3) .. and this is one in their favor, they were perhaps one of of the largest groups of 'essential workers' that still had to interact with many people even during the height of whatever we want to call that period early on where we were 'locked down'.