Does the MMR vaccine cause measles?

A viral tweet claims that the MMR vaccine causes measles, citing the package insert as evidence.

Listed in the insert is atypical measles, which is a very rare, serious form of measles in those who had received an older, inactivated form of the vaccine prior to 1967 and was subsequently exposed to measles. We have not seen a case since 1980. These inserts are legal documents, and not medical ones, and since atypical measles was once a very rare side effect, many years ago, it remains in the insert.

The current MMR shot uses a weakened live measles virus (genotype A) that is so mild it cannot make healthy people sick, and scientists can easily tell it apart from the wild strain (currently D8) virus that drives recent outbreaks. To date, there has never been a case of measles resulting from vaccination.

When measles spread this year in Texas and New Mexico, almost every case was in people who were not vaccinated. if the vaccine really caused measles, the opposite pattern would show up, but it never does.

A few vaccinated people may get a brief rash or low fever, and only those with severely weakened immune systems face a very small chance of a vaccine‑related illness, while wild measles regularly causes pneumonia, brain swelling, and even death.

After two doses, the MMR vaccine is about 97% effective against measles, and has helped cut global measles deaths by about 78% since 2000, proving the shot prevents disease instead of causing it.