DON'T MEASLES VACCINATIONS WORK? IF THEY DO WHY THE FEAR?

Regarding the recent furore surrounding child measles vaccinations and the suspicions surrounding the governments real intentions regarding enforced vaccination...

...how come, if these vaccinations are necessary and effective and the majority of children have already been voluntarily vaccinated, there's such a danger from unvaccinated children? Wouldn't the unvaccinated children just spread it amongst themselves as the rest of the kids already have their shots, right?

In other words, why would children already vaccinated be in dire peril of contracting measles? That makes no logical sense, provided the vaccinations actually work and/or they're not actually something else entirely.

The only explanation to this is that the vaccinations don't work and are something much more sinister. Having unvaccinated kids around exposes the uselessness of the vaccinations. The vaccinated kids contract measles anyway. And the constant threat of children being exposed creates the climate of fear necessary to allow the government to make them mandatory.

For whatever sinister purpose that might be.