The measles vaccine came out in the 1960s and as a result kids stopped getting measles. But that’s not all that happened. Childhood deaths from all diseases dropped markedly. Why did this happen?
Research has shown that the measles virus doesn’t just cause measles, it weakens the immune system overall, leaving children more susceptible to other diseases and more likely to die from them. By arming the immune system against measles it also protects against things like pneumonia and other illnesses that can result in death. And it lasts for years after inoculation.
Hat tip to Dan Lewis and his “Now I Know Newsletter”, which you should subscribe to right now (link on the right of the page).