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Why the world can't bring itself to destroy smallpox once and for all

Smallpox virus
Smallpox virus
UIG via Getty Images

For the sixth time, the World Health Organization has declined to destroy the smallpox virus once and for all.

Last week, officials met at the WHO's annual World Health Assembly to discuss many issues, including whether to destroy the last remaining lab samples of the smallpox virus — and eliminate any chance of it escaping. (The disease was eradicated back in 1980.) There were all sorts of arguments for and against.

Instead, officials decided to punt. On May 24, the World Health Assembly noted the existence of a report that summarized the results of three advisory groups from the fall of 2013 and that proposed to create yet another advisory group — to analyze the risks from synthetic biology. That's it.

There are lots of arguments for destroying the virus, which would eliminate the chance it could escape and possibly ravage billions of unvaccinated people. But there are also reasons that the WHO keeps punting, some officially spoken, some not.

1) The US and Russia may not trust each other to destroy their smallpox samples

The current battle over smallpox is often as much a political one as a health one. That's because the two labs that have smallpox are in the United States and Russia.

The World Health Organization consolidated the stocks into these labs not soon after smallpox was eradicated in 1980, creating a balanced Cold War stare-down between the two nations.

These two countries have been the most vocal about keeping their smallpox — usually citing reasons related to public health. But it's also possible that the United States and Russia don't trust each other to actually destroy the samples.

"I wouldn't trust the Russians as far as I could throw 'em," Peter Jarhling told me. He's a National Institutes of Health viruses expert who has advised the WHO on smallpox for more than a decade. He cites as evidence the time that Russia says it destroyed 200 samples of smallpox without letting the WHO verify it. Maybe Russia actually destroyed them. Or maybe they just took them off the books.

2) There could still be unofficial stocks of smallpox out there

The United States and Russia are the only countries that have official, WHO-approved samples of smallpox. But no independent body has ever verified that other countries destroyed their samples.

Some labs have found (and then killed) forgotten samples, suggesting that there could be other neglected samples that no one knows about yet.

3) Smallpox could survive in dead bodies


Ramses V, a pharaoh who had smallpox. Getty Images

Huge disclaimer: the risk for this one seems to be very low, according to experts, but it's too intriguing to not share. Smallpox, as far as viruses go, survives fairly well in dead tissue. And many people have been killed by smallpox — at least hundreds of millions of them.

Researchers have already found dead smallpox virus particles and DNA in bodies as old as ancient Egyptian pharaoh Ramses V, although they haven't found any live viruses. No one knows exactly how long smallpox can survive under these kinds of conditions.

One could consider the lack of live viruses unearthed so far as evidence that this scenario is unlikely. But in recent years, as this Nature piece reported, when an old smallpox scab turned up or workers uncovered a 19th century mummy of a smallpox victim, the CDC comes in to investigate using security precautions, just in case.

4) Scientific curiosity may prevent the destruction of smallpox stocks

The WHO is currently very strict about what smallpox research can be done. It has to pre-approve everything. And right now, it will only approve research for direct public health benefits, not for scientific curiosity's sake.

But scientific curiosity does exist, and it could be an unspoken factor that has led people to continue to postpone smallpox's kill date for decades.

Even if people sequenced the genomes of every single smallpox sample, that might not be the sum total of everything that can be learned about the organism. For example, people thought that all heritable information in humans was contained in the genome in DNA code. But that's not true. Now, it's become clear that there's a secondary level of information that is also passed down from generation to generation and influences how DNA is used: epigenetics.

Likewise, scientists don't know what they might miss if the last available smallpox samples are destroyed.

5) We could always recreate smallpox from genetic information

One could argue that in the information and genetics age, nothing really dies forever. It just dies until the technology to resurrect it appears. And for smallpox, that time is now.

The complete DNA sequences of roughly 50 smallpox samples are available to the general public. This means that people could make smallpox in the lab. "Someone could if they wished recreate live virus from scratch just from that public information," Grant McFadden says. He's a virologist at the University of Florida who doesn't work with live smallpox but has advised the WHO on smallpox research.

A sophisticated laboratory could resurrect smallpox right now. And at some point in the near future, anyone could. And if that is the case, then what would destroying the samples in these two labs in the US and Russia really accomplish? We might be able to destroy smallpox next year, but we won't be able to destroy it forever.

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