With the measles outbreaks in Minnesota and Ohio, and new survey data from KFF showing 44% of Republicans don't believe the measles vaccine should be mandatory and 14% of Republicans think the risks outweigh the benefits, I think it is important to remind people why measles is such a big deal.
Measles can cause immune amnesia after an infection. Infected memory T and B cells get destroyed by your body's immune response, essentially resetting your immunity. You can lose up to 80% of your antibodies. You end up with good immunity to Measles, but you lose immunity to other pathogens.
It normally takes a child 3 years to recover the lost immunity as they have to get infected/vaccinated again for all those previous viruses. In many cases such children die of those subsequent infections years later.
The epidemiological impact of this effect was massive. Researchers estimated this immune amnesia was partly responsible for half of childhood infectious disease deaths.
Researchers for ages didn't know why people seemed to be vulnerable after Measles infection despite seemingly the person recovering. It was only in the last few years they discovered the process going on due to the infection. A good reminder that the full risks of viruses can take awhile to fully grasp.