While everyone is sorry for any trouble he's going through
anyone with any knowledge of actual operations, either military or medical, can tell you that there are so many other things he could have been exposed to that caused these health problems. Vaccines are just something you've had your attention drawn to by current events.
I've had several friends who attributed problems they experienced to vaccines due to correlation, and both of them have since discovered the real cause of their illness because they let doctors actually try to heal them instead of deciding what the problem was in advance.
And you know what. I hate to tell you this, but it's my lived experience: sometimes people who are really fit and healthy, even like... world class level fitness... just develop a disease one day. And that's it. There's no more narrative to it. We're biological, there doesn't need to be a narrative justification for us getting sick. It just happens, and before vaccines it used to happen A LOT more.