Measles and immunological amnesia

A new paper in Science , by Michael Mina et al,  strongly suggests that measles messes up your immunological defenses for two or three years. This is the likely explanation for the fact that measles inoculation causes much greater decreases in child morbidity and mortality than you’d expect from preventing the deaths directly due to measles infection. The thought is that measles whacks the cells that carry immunological memory, leaving the kid ripe for reinfections.  I think there can be a similar effect with anti-cancer chemotherapy.

If correct, this means that measles is much nastier than previously thought. It must have played a significant role in the demographic collapse of long-isolated peoples (such as the Amerindians). Its advent may have played a role in the population decrease associated with the decline of the Classical world.  Even though it is relatively new (having split off from rinderpest a couple of thousand years ago) strong selection for resistance may have  favored some fairly expensive genetic defenses (something like sickle-cell) in Eurasian populations.

We already know of quite a few complex side effects of infectious disease, such the different kind of immunosuppression we see with AIDs, Burkitt’s lymphoma hitting kids with severe Epstein-Barr infections followed by malaria, acute dengue fever that requires a previous infection by a different strain of dengue, etc: there may well be other important interactions and side effects, news of which has not yet come to Harvard.

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14 Responses to Measles and immunological amnesia

  1. JCR says:

    Wiki says, “The measles virus evolved from the formerly widespread rinderpest virus, which infects cattle.[2] Sequence analysis has suggested that the two viruses most probably diverged in the 11th and 12th centuries, though the periods as early as the 5th century fall within the 95% confidence interval of these calculations.[2]” You are saying the split was much earlier?

      • Interesting paper. To quote “The precise age of measles remains elusive. The domestication of cattle 10,000 years ago provided the necessary exposure to RPV, and the development of agriculture allowed populations to reach sizes necessary to sustain
        an epidemic.”

        Genetic germ warfare played a huge part in anointing winners and losers in population shifts. This blog seems to be the place to come to for the latest updates. Other sciences seem to be bogged down, all the lowest fruits have been picked off the tree, but not genetics.

  2. Hahvahd, if that was a Lehrer reference.

  3. Fourth doorman of the apocalypse says:

    This is interesting.

    I grew up in a country that did not see the Measles vaccine until 1969 and where I lived, probably much later.

    We used to play in the dirt quite a lot and I lived in a place that is about 12 degrees south of the Equator.

    I am pretty sure I got Measles, but I don’t recall an extended period of sickness and never had to stay home from school (and I would have remembered that), but I do recall having weird dreams for a while around age 6/7. I can remember breaking my arm at age five and counting backwards from 10 to about 8 or 7 when they put me under to set it and apply a cast.

    Is it possible that not all of us are affected by Measles the same way?

    • ursiform says:

      Some people get much sicker from measles than others. The symptoms can range from mild to death*, after all. Your mileage may vary …

      I had the measles, but was much sicker with chicken pox. Or should I blame the chicken pox on the measles?

      *Note that in the case of death there is no further compromise of the immune system.

    • You might have too young to remember. I only very dimly recall having measles. My mother remembered and told me.

    • mysterian says:

      I had the measles in the second grade. I was out of school for three weeks. It was the sickest I’ve ever been. The day the spots would appeared I had a fever of 106. My folks put me in an ice bath and after the ice had melted my temp was 104 and the red spots had appeared…

      I can easily see a city state being laid low by such an epidemic disease..

  4. Fourth doorman of the apocalypse says:

    I notice that Measles is one of those viruses that expresses Heamagglutin on is surface, although it seems to be different to the HA on the influenza virus.

    One line of defense against influenza seems to be the production of mucus laced with sialic acid, so is it possible that a line of defense against measles is the production of mucus laced with some portion of CD46?

  5. Justin says:

    So the idea is measles may have softened up the western empire? Or are you thinking measles was behind Justinian’s plague?

  6. What, are you telling me that just letting my kid catch measles isn’t the best thing ever?

  7. dearieme says:

    Is there any evidence that the expanding Indo-Europeans (“Aryans”) carried diseases with them that helped destroy previous populations? Something horse-related, perhaps?

  8. Fourth doorman of the apocalypse says:

    The article says:

    Measles kills about 140,000 people worldwide every year, but the millions of kids who have survived the disease aren’t in the clear.

    To put that into context, that is below 1/10000 it seems. Even with the multiplier effect, perhaps still below 1/10000.

    Abortion seems more lethal, with one site claiming slightly over 1M in the US in 2011.

  9. Brian says:

    At age five I had measles soon followed by chicken pox, although that could have been chance. It was the Fourth of July, and since illness excluded me from the general mayhem (facilitated by the robust fireworks of the day) I became morose enough to consider television. But my pediatrician told my parents that TV-watching during measles could cause blindness, so I ended up sneaking comic books under the bed. Sometime between then and the beginning of school this townie had to spend a long, boring afternoon in the country. While my folks were visiting indoors, my eight-year-older brother was detailed to prevent me from falling into the well, etc, while we explored the farm. After this wore thin, I killed the rest of time chasing the chickens. During the long drive back I started itching like crazy. When we got home my father pronounced chicken pox, and slathered me with calamine. My brother asked me, with perfect deadpan, what else I could expect given the way I spent the afternoon. Sounded reasonable to me.

    It was months before I caught on.

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