You don't say anything to them ( I count myself amongst 'those' people)
If you want to inject god knows what without any research whatsoever into your child, you go ahead. Your call as a parent.
Some I have injected. Others I have steered well clear of.
Overall though, I like the fact that 'anti-vaxxers' actually do look into what they're injecting. I find it somewhat bizarre that people who are so pro-vaccine generally have no clue whatsoever as to what's in that needle. Cue lots of FB updates a day later - my baby is so poorly, high temp, just not himself blah blah. What did he have? Oh just his regular injections. Well, what exactly? Well the ones you have when your baby is 16 weeks etc etc So you don't actually know what was in that needle??
Some people are incredibly naive though to believe that everything we are pushed to inject is for our own good. Why on earth does a 1 yr old need a rubella jab???
Nobody bats an eyelid if your child gets chickenpox (even though there is an available vaccine) yet if your child gets measles, omg, why weren't they vaccinated, how dangerous/stupid etc etc. Both illnesses can be mild. Both illnesses can be serious. Total media control over how most people react to them though?
Whooping Cough - my son contracted this and was incredibly poorly, kept in hospital. Very nasty. Before everyone loses their mind, he had been vaccinated. It didn't work clearly.
I'm confident in my choices and the vaccines we have had, and the one we haven't. I don't feel the need to justify this to anyone. All I would say though, if you had met a parent of a vaccine damaged child (try my mum) you would have very different views to the ones you have now.