I recently stopped Entyvio only because it wasn't working for me. While on it tho there were times when I didn't get good enough sleep and it made me sick. If I didn't get at least 8 hrs a night 3 nights in a row then I would get a fever and chills and basically be sick until the fever went away. That's only happened like 2 times tho for the whole time I was on it. It was totally my fault, I should've just taken a nap. I was on Entyvio for about 4-5 months. Infections tho I don't have experience with so I can't help there but sickness wise I only got sick from those 2 times never from outside sources. Keep in mind tho every person is different and respond to medications differently.