My high school understanding focused on the outcome: the vaccinated immune system wins before the disease gets noticeable. I’m trying to go deeper: measles starts to grow, my body responds, and there’s a battle. And that may have happened a dozen times or more since I got my shots?

Measles isn’t very common in the US so it’s hard to say how much you may have been exposed, if at all. You might know if you have been. For more common diseases, yes.

This is the argument that the antivax community have used for years. It's an invalid argument because even in a region where there's been very few cases, that can literally all change overnight. All it takes is a couple infected passengers at an airport, low local vax rates and you have an outbreak.

I wasn’t making an argument, I was responding to the question of whether they might have been exposed a dozen or more times. It’s increasingly likely, but in past years much less so.

In other words, can’t necessarily be certain we’ve all got a lot of protection resulting from past exposure.

I shared my 1963 date mainly to add to the possibility of exposure in the years before measles nearly vanished. I agree “a dozen” was still probably excessive as a guess.

Honestly I don’t know, can’t hurt to get a booster for those of us born before it was a 2 shot series. The vast majority of people getting sick were unvaccinated.

Yes, most were unvaccinated, but there are some few who had 1 vaccine in the series and experienced a breakthrough infection. Measles can decimate immunity to other infections by way of immune amnesia and possibly cause fatal SSPE months-years later. www.uclahealth.org/news/article...

To clarify, I got a full MMR course in 1985, based on assuming I hadn’t gotten any of them. Recently, I saw a signed statement from my preschool pediatrician, telling me I got the measles vaccine the first year it was available. So I’m sturdy unless 40 years since the last round is too long.

Measles can be transmitted for days before a person is aware they're sick. It can also hang in air indoors for up to 2hrs after an infected person has been there. With lower vaccination rates we're seeing more breakthrough infections. People need to be aware the possibility of exposure is anywhere.