It's typical. Entire pro-vax threads are allowed, but as soon as someone presents a different point of view the thread is locked and 'problematic' posts removed.
Why belief system? We read leaflets listing what are painkillers made from and what side effects might come out from taking them and yet we don't read leaflets when we take vaccinations. I personally don't know a single person who would read the documentation before taking vaccination. Acting like this is basically committing statement of faith.
Pied Piper to one side. Rodeo clown to the other.
Protect yourself. Don't walk into the trap.