The Little I Know: Rav Shmuel shlit”a was not anti-vaccines. He was not an advocate for them but was not against them. He also consulted with Rav Chaim Kanievsky shlit”a who concurred with him. And they addressed the issue of a school stopping unvaccinated kids from entering the school.
Rav Shmuel shlitah said that Yeshivas/BY may not stop unvaccinated children from attending Yeshiva/BY.
You don’t consider that an anti-vax position?