Just this week, an outbreak of mumps among more than 1,000 people in New Jersey and New York has raised alarm among infectious disease authorities. The outbreak itself is not unusual, though. What's unusual is that the health authorities slipped up and admitted that most of the people infected with mumps had already been vaccinated against mumps. In Ocean County health department, New Jersey, county spokeswoman Leslie Terjesen told CNN that 77% of those who caught mumps had already been vaccinated against mumps.

Merck, the worlds only manufacturer of the single MMR vaccines has confirmed that it has stopped production of Mumpsvax, meaning parents will no longer be able to vaccinate their children against mumps. A spokesperson for the company confirmed “Merck will not resume the production of the monovalent measles, mumps or rubella vaccines.” There are claims that Merck was put under pressure by the UK government to stop making Mumpsvax because it wants all parents to have the combined MMR jab.