Seminole, Texas CNN  —  Gaines County is a vast, flat expanse far in the west of Texas: more than 1,500 square miles of sparsely populated farmland. And right now, this is the epicenter of a measles outbreak the likes of which this state hasn’t seen in more than 30 years. Many here say the virus has spread quickly among the Mennonites, a tight-knit Anabaptist community that works much of this land. “That’s the biggest cohort of the population that is unvaccinated,” said Dr. Leila Myrick, a