I Got a Smallpox Vaccination as a Child. Am I Safe From Monkeypox?

Unlike the coronavirus, monkeypox isn’t new—we’ve had a vaccine for it for years.

Exit COVID, enter monkeypox. Makes you wish we’d saved some of the smallpox vaccine we flushed after smallpox was eradicated 40 years ago, huh? Lucky me, I was born before then, so I got the smallpox jab as a child. Am I covered for the monkey version? —Shocked by the Monkey

As much as I’d like to agree with your assessment that COVID-19 has left the building, Shocked, the fact that I’m still coughing up pieces of my lungs after (finally) contracting it last week suggests that there’s still some life in the old plague yet.

Not that it matters. There’s no law that says one pandemic has to be over before the next one begins; if monkeypox wants to wipe us off the planet, it can start whenever it likes. Fortunately, that doomsday scenario doesn’t seem likely—though I can certainly understand why a COVID-scarred world might be jumpy about a new virus.

Unlike the coronavirus, however, monkeypox isn’t new—we’ve had a vaccine for it for years. Moreover, its resurgence isn’t a surprise; epidemiologists have been predicting it ever since smallpox went the way of the three-martini lunch (RIP).

Since the smallpox vaccine also conferred immunity for monkeypox, the push that eradicated smallpox also kept the monkey version at bay—until all the folks like you (and, ahem, me) old enough to have had that smallpox shot started dying off, leaving behind a population increasingly vulnerable to whatever ambitious young pox virus might come along next.

By the way, we didn’t actually flush all that smallpox vaccine—the U.S. still has 100 million doses, presumably as a hedge against the possibility of weaponized smallpox. (Military personnel are vaccinated for the same reason.)

But you wanted to know if a vaccine you got back when barbers still did amputations will stave off monkeypox. Well, if COVID has taught us anything, it’s how frequently the accepted scientific answer to a seemingly straightforward medical question is, “Who the fuck knows?”

The long-standing CDC line is that you shouldn’t count on immunity from a smallpox vaccine lasting more than five years. However, some recent studies (“in the last 20 years” counts as “recent” in smallpox research) found measures of immunity only slightly diminished after as many as 88 years. Are your toothless, old-timey antibodies, shouting at the smallpox virus to get off their lawn, as good as fresh ones? No, but they’re probably better than nothing—and if they manage to form an HOA, watch out.

Questions? Send them to dr.know@wweek.com.