Decades ago, attaining immunity from infectious diseases was little more than a game of chance. For some, exposure to disease caused severe illness. Others walked away unscathed. Either way, the immune system churned out protective antibodies to help the body win future bets against infectious bugs. Compared with receiving today's lineup of vaccines, “that's a harsh way to get immunized,” observes infectious diseases specialist William Schaffner, MD, of Vanderbilt University School of Medicine in Nashville, Tenn.
Voelker R. Campaign Aims to Boost Adult Vaccinations. JAMA. 2009;301(19):1976. doi:10.1001/jama.2009.672