Scientists find the strangest things when they're cleaning out old refrigerators. Like… smallpox.
Last week, employees at the National Institutes of Health campus in Bethesda, Maryland were cleaning out an old storage room when they happened upon six glass vials of smallpox that had been packed up in a cardboard box, placed in a refrigerator, and then forgotten.
The vials didn't appear to pose any health threat. They were all sealed, and the Centers for Disease Control and Prevention says it hasn't found any exposure risk to either employees or the public. It's even possible that the viruses had already been dead for many years.
But what's unnerving is that loose samples of smallpox aren't supposed to exist. Back in 1980, after public-health officials had eradicated smallpox around the world, the World Health Organization consolidated the last few remaining samples into two labs: a CDC lab in Atlanta and a Russian lab in Novosibirsk, Siberia. All other samples of smallpox were assumed to be destroyed.
It's not clear how this particular sample managed to evade detection for so long. The vials appear to date from the 1950s, officials said. The laboratory where the vials were found was transferred from the NIH to the Food and Drug Administration back in 1972. The samples then remained undiscovered until this year, when FDA officials were preparing to move the lab from its current location to the FDA's main campus.
Why forgotten smallpox samples are a big deal
This appears to be the first time that unaccounted-for smallpox has been discovered in the United States. But other "forgotten" stores of smallpox have turned up in places like Eastern Europe. And it raises the possibility that more may be out there.
Lately, there's been a ferocious debate about whether the last two labs in the United States and Russia should destroy their official stockpiles of smallpox. The case for destruction is that this disease is brutal and could escape. (Smallpox needs to be kept cold to stay alive, but it can usually remain deadly even after it's frozen.) The case against destruction — maybe we need those samples for further research.
But as my colleague Susannah Locke pointed out, there's a third consideration here. It's entirely possible that the US and Russia won't be able to destroy smallpox once and for all — if they're not the only ones with the virus. Perhaps there are still yet more unaccounted-for samples out there, lurking in the storage closets of some lab. Alternatively, there's the admittedly remote possibility that some rogue smallpox viruses still exist on dead bodies. (The CDC often takes security precautions whenever archaeologists chance upon an old mummy with a smallpox scab.)
It's unclear whether the smallpox virus samples found in the Bethesda lab are alive or dead — there seems to be some disagreement as to whether the vials were kept in cold storage all this time or at room temperature (the latter would have likely killed the virus). In either case, the samples are being taken to CDC headquarters in Atlanta for testing and will then be destroyed.
There's a good reason for all that precaution: Smallpox was one of the deadliest diseases of the twentieth century, responsible for some 300 million deaths. The virus killed more than 30 percent of the people it infected and left survivors with tell-tale facial scarring. And most young people today are unvaccinated, given that the last known case was way back in 1978.