There's no telling actually. My mom and I have theories. I was diagnosed with rubella days after the MMR booster, but the doc said it was fine to continue with the rest. My mom thinks the one that gave me rheumatoid arthritis was the TDaP and we have no idea which gave me the Hashimoto's thyroiditis and other autoimmune stuff. I'm guessing all of them combined did me in. I'm in my 40s and it has been hard dealing with it all these years.