http://www.medicinenet.com/script/main/art.asp?articlekey=53724
http://www.latimes.com/news/local/la-me-vaccine2-2008may02,0,6944471.story
Also the reason un-vaccinated people aren't catching either of the above listed diseases is simply because most of us are vaccinated, so the likelihood of the disease being spread is minimal. Though people who at one time received vaccines, can still contact a disease after a long enough period of time.