I'm a Pureblood. (And proud of it!) My mom's a Squib. My dad's a Squib. My little sisters a Muggle-Born. My older brother is a Dursley. Most of my friends are Dursley. That is why i am such a Deatheater when i talk to them. I am weird.
Here are the facts. By Maki Naro. Vaccinations in short are tricks played on the body to think it is sick. Thus it sends out the proper enzymes to fight the virus in turn building an immunity against the disease. To conclude, vaccines WORK.