Measles vaccine while on Entyvio?

Some of us have taken live-vaccines while on biologics, like the live-shingles vaccine (before the dead version became available). I'd discuss this with your gasteroenteroligist and see what he/she thinks. Certainly not wholly without any risk at all.

A "live" vaccine is best at attacking a non-human host. When you/I take a live virus it is poorly adapted to survive and reproduce within us, making it an easy target for our immune systems. With biologics, our immune system is weakened a bit, but still works. There's a small chance that a weakened immune system and weakened virus might give the virus an edge, and we get sick with what we're being vaccinated against.