Thanks! I learned a lot from writing this article and have learned even more since then.  One thing I forgot to add in this article is that the MMR vaccine insert states that the second dose is only if the first dose doesn't take. This means that those medical professionals pushing for two doses because the CDC lists it in their schedule are most likely violating the product instructions from Merck since they rarely conduct a test to see if the first dose took. This means many children are going through unnecessary medical procedures and being subjected to increased risks of adverse reactions.