While public health authorities in Texas and elsewhere are doing their best to contain the latest outbreaks, RFK Jr. is going on Fox News talking up the benefits (?!?) of measles infection and making the vaccine sound as bad as the disease.

The measles vaccine—which is technically the measles, mumps, and rubella or MMR vaccine—is usually administered during childhood, and while it is considered incredibly effective at preventing the virus, immunity can still wane over time. So, do you need to be revaccinated for measles or should you consider yourself protected if you got it as a kid?