What's behind the 'anti-vax' movement? This spring saw the first death from measles in the United States in 12 years.
Measles infections there are at their highest since the disease was supposedly eradicated. The reason for this is that the number of people vaccinated against measles has been falling.
More and more parents have been refusing to immunise their children. The influence of a loose group of fringe campaigners against immunisation - "anti-vaxxers", as they're known - has been spreading. And with it, disease. BBC News