Is anybody noticing a pattern here?
In 1977, children started receiving a one-dose mumps vaccine. Initially, rates of mumps fell dramatically, and health officials were congratulating themselves that they were on the road to eradicating another disease.
Then, in the late 1980s, there were unexpected outbreaks of mumps among adolescents and young adults who had been vaccinated. And so, in 1990, our health officals introduced the two-dose vaccine. Almost immediately, mumps cases fell so dramatically that everyone was predicting that mumps would be wiped out by 2010.
Then, in 2006, there was an unexpected outbreak of mumps among adolescents and young adults who had been vaccinated twice. A total of 6,584 cases among college-age kids was reported, which suggests there were many more that were never reported.
And so officials from America's Centers for Disease Control and Prevention (CDC) are suggesting the introduction of a triple vaccine "to avert outbreaks and achieve the elimination of mumps".
I think you can guess the rest.