Mon, 16 Jul 2012 11:53 UTC The oft-parroted sound bite - we need herd immunity - implies that if ninety five percent of the population can become immune to a disease via vaccination, target immunity levels will be met and diseases will either be eradicated or controlled. This sound bite is the most commonly pulled weapon used by the vaccinators, only second to smallpox and polio were eradicated by vaccination. Herd immunity is the trump card for the defense of vaccination on TV, Internet, medical journals and newspapers as to why we should be vaccinated over and over throughout our lives, with an ever-increasing number of vaccines.