Non vaccinated children a risk to vaccinated children...explain this to me

[Artechim]

Non vaccinated children increases the prevalence of the disease because they have less immunity to that disease than a vaccinated child. Vaccination is not 100% effective, so when the disease is more common then the amount of vaccinated children that also get the disease will increase. However, the effects are apparently less in a vaccinated child.

I was vaccinated and had both measles and mumps as a child.

ETA, they may also worry about younger children that have yet to be vaccinated, such as whooping cough in a newborn.

[little_O]

Ok I see I see. At least I can understand their viewpoint now, couldn't work it out