What does society do when one person's behavior puts the greater  community at risk? We make them stop. We pass laws, or impose economic  rules or find some other way to discourage individual behaviors that  threaten the greater common good. You don't get to drive drunk. You  don't get to smoke in public places. You don't even get to leave your  house if you catch some particularly infectious disease.
Then what should we do about people who decline vaccination  for themselves or their children and put the public at risk by fueling  the resurgence of nearly eradicated diseases? Isn't this the same thing:  one person's perception of risk producing behaviors that put others at  risk? Of course it is. Isn't it time for society to say we need to  regulate the risk created by the fear of vaccines? Yes, it is.
The evidence is overwhelming that declining vaccination rates are contributing to outbreaks of disease. Take just one example, measles.  The World Health Organization reports outbreaks in countries where  vaccination rates have gone down, including France (7,000 cases so far  this year, more than in all of 2010), Belgium, Germany, Romania, Serbia,  Spain, Macedonia and Turkey. There have already been 334 measles cases  in England and Wales this year, compared with 33 all of last year. The  U.S. has seen 118 cases as of mid-May, compared with 56 cases a year  from 2001 to 2008.
http://www.latimes.com/news/opinion/commentary/la-oe-ropeik-vaccines-20110718,0,4240440.story