There was no small number of Air Force pilots who left the Air Force rather than take the anthrax vaccine over fears that they would become medically unable to perform their civilian job; nobody then (or now, certainly) thought that their fears were baseless.
I hope your brother is able to return safely to the cockpit. If he was compelled to take this shot by his employer, it would be incredibly ironic if it ended his career.
Yes you are correct. My brother was compelled to get the vaccination and he was not worried about it. Now this weird reaction.
I worked as a hazmat team leader for many years. I had ten times as many vaccinations as most people and never had a problem. Strangely enough many of the my former coworkers and subordinates still working Hazmat have refused to get the experimental Covid vaccines. The more knowledgeable people are about them, the more hesitant that they are to become part of this huge experiment.