Examination of child mortality rates in the U.S., U.K., and Denmark in the decades before and after the introduction of the measles vaccine revealed that nearly half of all childhood deaths from infectious disease could be related to MV infection when the disease was prevalent. That means infections other than measles resulted in death, due to the MV effect on the immune system.

MV = measles virus

Well that’s way worse than I thought.

Yes, it kills most if not all memory immune cells.