cofty: anti-vaxxers, flat-earthers, creationists, 9/11 conspiracy nutters - they are all the same sort.
The difference is that anti-vaxxers are a threat to children.
I would add "noblooders" to your list, Cofty.
All of the above are irrational people. They are more concerned with possible "harmful ingredients" than they are with the benefits of vaccines. For one thing, death from contracting a preventable disease is a far more harmful outcome than putting a vaccination into the body. Just like blood transfusions, they ignore the benefits and focus on a negligible possibility. Scared of their own shadow.
I was astounded when I read an article that parents are taking their children to "chicken pox parties". They actually believe that introducing a virus into their child's body is a better outcome than preventing a virus from permanently taking up residence in their child. They actually believe that chicken pox is a harmless childhood disease and have ignored completely that the same virus has a +30% chance of causing an adult who carries it untold suffering later in life. Adults who have had chicken pox as a child have a one in three chance of that virus erupting into a shingles outbreak. And yet those parents think they are doing their kids a favor by giving them chicken pox.
The anti-vax movement is a cult.