Ken Alibek explains (in Biohazard) that he has lost all sense of smell and had the broadest range of allergies of anyone he knows:
I can’t eat butter, cheese, eggs, mayonnaise, sausages, chocolate, or candy. I swallow two or three pills of anti-allergy medicine a day—more on bad days, when my sinuses start to drain. Every morning, I rub ointment over my face, neck, and hands to give my skin the natural lubricants it has lost. The countless vaccinations I received against anthrax, plague, and tularemia weakened my resistance to disease and probably shortened my life.
He’s writing that long before the current anti-vaccine craze.