Does the MMR cause measles outbreaks?

A large outbreak of measles in Texas and now New Mexico has anti-vaxxers claiming  that the measles vaccine can spread the virus to others, causing the recent outbreak.

The MMR vaccine, which contains a weakened form of the virus. While this weakened virus can be detected in the body after vaccination, it is highly unlikely that is will cause disease in other people. In fact, there has never been a confirmed case of the measles vaccine causing someone else to contract the disease.

The recent measles outbreaks in Texas and New Mexico has spread mostly among unvaccinated people. In Texas, out of 124 reported cases, the vast majority were in unvaccinated, with only five cases in vaccinated people.

We can conclude that the vaccine people are getting does not cause measles in them. If the measles vaccine were spreading the disease, we would expect to see higher rates in vaccinated people, but the opposite is true. We also know that all samples tested in the outbreak have come back as genotype D8, a known strain of the wild measles viruses. The genotype for the vaccine virus is Type A. So it really isn’t the vaccine. It’s the unvaccinated.