> I'm not a doctor, but if the rest of us vaccinate our kids, won't they NOT GET SICK?
No. Many vaccines are very effective, but not 100% effective. In addition, while vaccines are generally safe, there are people people that are not "anti-vaxxers" (or their children) who are not vaccinated, including those two young to receive a particular vaccine or those who do to particular health condition cannot safely receive a particular vaccine. General vaccination not only reduces the probability (but not to zero) of those vaccinated getting sick if exposed to the disease, by doing so it reduces the probability of them exposing others to the disease.
If vaccination is not general to all those who can safely receive it, its effectiveness in preventing disease both in those who are vaccinated and in those who are not vaccinated is reduced, because both the vaccinated and the non-vaccinated are more likely to be exposed to the disease than they would be if vaccination was general.
No. Many vaccines are very effective, but not 100% effective. In addition, while vaccines are generally safe, there are people people that are not "anti-vaxxers" (or their children) who are not vaccinated, including those two young to receive a particular vaccine or those who do to particular health condition cannot safely receive a particular vaccine. General vaccination not only reduces the probability (but not to zero) of those vaccinated getting sick if exposed to the disease, by doing so it reduces the probability of them exposing others to the disease.
If vaccination is not general to all those who can safely receive it, its effectiveness in preventing disease both in those who are vaccinated and in those who are not vaccinated is reduced, because both the vaccinated and the non-vaccinated are more likely to be exposed to the disease than they would be if vaccination was general.