The
administration of antigenic material to produce immunity, or close to immunity, to a disease.
Only people in third world countries who can't afford it and
retarded people who either don't understand science or are religious nutjobs don't get vaccines. Some wackos still think it causes like autism - but there is absolutely no link between the two and these people are both wrong and doing damage to the research that could be
getting done on the real reasons for autism.