As I said, pilots aren't going to take experimental treatments because if they can't pass a Class 1 physical, they're done flying commercially. Most pilots don't want to do anything else but fly.
I witnessed entire squadrons refuse the Anthrax shots because of the risk.
I believe my assumption that these entry level pilot trainees are vaccinated is more likely than your assumption that they are not. US News is just the first link I found; there were other sources with the same information. Like many other issues these days if we can’t trust any source information the discussion is pretty much pointless.