During a measles epidemic. I work for a state elected official. The push back was unbelievable. But it didn't come from religious organizations or churches, temples, synagogues or mosques. I think 95% of the anti-vaxxers used "religion " as their excuse. When it was gone they all complained that they couldn't get medical exemptions. Of course they couldn't. They didn't need it.
The religious organizations we heard from, including the Christian Science church, all supported removing the exemption.