Herd immunity

It’s always surprising to me when a term of scientific/medical jargon becomes part of public discourse. A recent example is “herd immunity.” Historically, epidemics like plague or smallpox would rage through a naïve population until enough survivors, who acquired resistance because of infection, made it impossible for the bacteria or virus to jump to another naïve victim. The epidemic would end, but it would re-appears when the next generation of unexposed people reached adulthood.

A concomitant of herd immunity through natural infections is death, and in the case of polio, the survivors often have lifelong disability. Enter vaccination. Thanks to vaccines, herd immunity can be achieved without the massive loss of life that attends herd immunity through infection. Smallpox was eradicated because of vaccines. Polio is close to extinction because of vaccines.

The anti-vaxxers have hijacked the idea of herd immunity for political purposes. Setting aside some the more risible claims—the vaccines implant chips so Bill Gates knows where you are, or cause you to express luciferase, the biblical mark of the beast—the claim that vaccines are “unnatural” and herd immunity through infection is superior because it is natural deserves special contempt. Natural infection kills people, vaccines don’t. Even someone who chooses to tempt fate (Matthew 4:7, peeps) is also putting others at risk.

One of more seductive claims is that natural infection is as good as vaccination, so why not roll the dice, and if you survive, you’re “vaccinated.” While the data are variable on the comparison, what is not in dispute is that both vaccine-induced and infection-induced immunity wanes over time, although vaccine immunity seems to be more durable. In the case of vaccine-induced immunity, the answer is a booster, which carries little or no risk. In the case of infection-induced immunity, there’s a sizable risk that you’ll die in the process.

Iran chose to politicize vaccination, and is paying the price. In some areas, more infections have been reported than people who live in the area, which means there are re-infections. And it is all but certain that infections are under-reported in Iran, for the same political reasons that the government rejected western vaccines. A similar thing will happen in states that are discouraging mandatory vaccination and masking. I suspect that if you pointed out that they have that in common with Iran, they wouldn’t take the comparison kindly.

This has been your TED Talk for today.

https://www.yahoo.com/news/iran-herd-immunity-flop-very-100437929.html