5 coaches testing positive seems within normal statistics.
What are you basing this on? Not saying you're wrong, just that my intuition was leaning strongly in the "this is statistically very weird" direction.
As you start zooming out, five on one team's coaching staff probably becomes nothing more than statistical noise.
Zoom out from the coaching staff to the Yankees' coaches + players + other on-field personnel. Is it now 5 out of 50? Could be.
Zoom out to all Yankees' employees -- the group above plus scouts, analytics, equipment, marketing, etc. Is it now, say, 7 out of 250?
Zoom out to all MLB employees -- basically the group above x 30. Is it now several dozen out of 7,000 or so?
...
Add to that a point I made in the PF coronavirus thread:
Plus, it matter A LOT how these Yankee coaches are experiencing their infections. Did they get laid low? Do they just have annoying symptoms that got IDed as COVID only upon a test? Do they feel fine, and would have never known they were infected without a test?
That kind of stuff matters -- if vaccinated people end up with COVID, but the infection is mild or even unnoticed ... the vaccine is still doing its job and is still effective.
The vaccine doesn't insta-kill coronaviruses as they land on your epithelium. The vaccine gets your body to make in advance as many antibodies as it can**, AND this process helps your bodies T-cells "remember" how to make more coronavirus antibodies when needed. There is a lag between (a) when the virus gets into your body (breathed in typically, settling in the nasal passages or bronchi) and (b) the time your vaccine-initiated antibodies get to work. And if your particular immune system was below average before your vaccination, maybe your body's post-vaccine response to the coronavirus virions is somewhat dampened compared to others' post-vaccine response. Not dampened enough to where you get badly ill and all that ... just dampened enough so that the virions have a little time to multiply and show up on a PCR test before getting wiped out by your immune system in the end.
** and this ability to manufacture antibodies varies a lot from person to person like so many other human traits.