Question

Why are those who cannot be vaccinated for childhood diseases safer if everyone around them is vaccinated?

Answer 1

So then scientists will have more pressure to find a cure or vaccinate them

Answer 2

Answer: They're safe, but the people around them aren't.

Explanation:

If other people are immune to a virus, but a particular person isn't, then there is a good chance if the particular person contracts the virus, there will be a mass pandemic.