Vaccination: It Does Affect Other People

Child with measles http://phil.cdc.gov/phil/home.asp

Browsing across my Facebook feed I came across this comment on the subject of childhood vaccination:

...I don't believe that a person's right to choose what is put into their child's body should be taken away though. Why should I be worried about unvaccinated children when my child is vaccinated? He should be protected if the doctors & scientists are so smart... -Unnamed Facebook friend's friend.