How do you deal with non vax kids

I'm having my baby in December and my sil has 3 kids she will be having her 4th in September their ages range from 5-newborn and non of them are vaccinated. I'm due during flu season and my cousin told me babies can't get their measles shot until one year old. How am I going to keep my baby from the other kids for an entire year? Anyone else going through this situation? They also just moved back from Texas which the area had a huge measles outbreak while they were living there.