Yes, clearly getting measles is worse than being taken from your family as a child...
Getting measles is worse than your parents being compelled by law to stop being idiots and get you vaccinated against measles.
Children are not property of their parents. They are wards of their parents and when parents exercise poor judgment in caring or not caring for them, it is the right and obligation of the government, in the public interest, to intervene.
This is no different than the idiots in Pakistan who refuse to let their kids get the polio vaccine because clearly it's all a big trick by the Imperialist-Zionist Plot to Undermine Our Traditional Islamic Values. Replace "Imperialist-Zionist" with "Liberal-UN-NWO" and "Islamic" with "Christian/American."
I doubt that these people are NWO conspiracy theorists. More likely just gullible, easily frightened parents.