MMR is one of the most dangerous vaccines and he might have gotten it from the vaccine. I got extreme ME/CFS shortly after receiving the shot. I immediately had to quit the College I was studying at, quit my job, and quit the bands I was playing in, and also quit all physical activities I have always done such as running, riding, windsurfing, dancing, aerobics and bicycling. A pretty sudden change from totally healthy and energetic to totally bedridden I must say. There is a ton of info on vaccines on the net.
Here is an interview with an ex vaccine researcher with Jon Rappoport