Having the measles reduces risk of allergies:
So, everyone else vaxxing their kids is putting my kids at risk for allergies.(being snarky here, ok) Very interesting read!!
Doesn't exactly fall under the same category as "getting sick" but Hilary Butler had a chapter in one of her books about how carriage of certain types of bacteria seem to prevent colonisation with the others. It was the Hib-Pc-Staph continuum I believe.