Infusion Transition Period?

Hello, I started Entyvio infusions back in July and I’ve barely gotten better, talked to my doc and am currently submitting some tests but it seems like I’ll likely be switching to a different infusion medication. I just was curious if there’s like a certain time period I have to wait between my last infusion and starting a new medication? Before Entyvio I was in a horrible flare up and I REALLY don’t want to have to go back to that while I wait to start another medication.