There has recently been (more) discussion about whether the US should destroy its remaining stocks of the smallpox virus:
Like measles, smallpox is a human-only pathogen. There are not bat or pig reservoirs out there-- smallpox is only in people. So with effective, world-wide vaccination efforts, we eradicated smallpox.
It no longer infects humans, and hasnt for a long time. If you were born >1982, you probably never even had to get the vaccine.
... But the virus is not extinct. It still exists in one laboratory in the US, and one laboratory in Russia.
"WHY WOULD YOU NOT DESTROY IT ALL????" some of you might ask.
Isnt keeping smallpox alive just *asking* for some crazy person to use it as a biological weapon??
*shrug* Maybe. Crazy people do crazy things.
But scientists do scientific things.
Even though smallpox is eradicated, scientists have still been studying it, using it to design *better* smallpox vaccines and anti-smallpox drugs, should we ever need them. Yes, there is a crazy person who could expose us all to smallpox... or more likely, humans could be exposed to a new kind of -pox from another animal. In fact, that is exactly what is occurring, right now:
So first and foremost, we shouldnt destroy it, because we understand it. Studying smallpox vs new -pox could rapidly aid us in case of a catastrophic zoonosis in the future.
Also, who knows what we could do with smallpox in the future. Scientists are using genetically modified viruses to treat, if not outright cure, countless diseases these days. If someone would have told a researcher in 1985 that we would, one day, use HIV as a *safe* vector for gene therapy, they would have thought you were insane. And yet that is where we are.
Smallpox viruses are relatively HUGE. HIV is only ~10,000 nucleotides long. Another common gene therapy vector, Adenoassociated virus, is only ~5,000. Smallpox is 186,000 nucleotides long-- we could cram a LOT of functional genes in there, if we needed to, for some reason, maybe. The point is, we have domesticated and genetically modified lots of viruses to perform miraculous tricks, recently.
Smallpox might save our butts one day.
Thats the practical side of things, but then there is also the romantic side. Smallpox is a creature that has been evolving on this planet for the past >4 billion years. Just like us. Just like Bengal tigers. Just like dolphins and rhinos and wolves and whales and other creatures we fight to protect from extinction. I see no point in blowing a safely contained creature out of existence. I dont think I could kill the last smallpox virus any more than I could kill the last koala.
Ultimately, however, all of these philosophical and scientific deliberations are an exercise in futility. We could probably generate smallpox de novo, out of extinction, using gene synthesis if we really *had* to.
"Smallpox is a creature that has been evolving on this planet for the past >4 billion years. Just like us."
Viruses and prions fail to fall into any one of the three commonly-known categories "animal, mineral, or vegetable" because they are non-cellular yet adaptive pathogens: they are parasitic and are totally different from a cuddly koala.
Cancer has been evolving for a very long time and I would willing volunteer to destroy the very last instance of it (having lost a very dear friend to it).
There is absolutely nothing that I find even remotely romantic about the viruses, prions, cancers, and other deadly infectious agents that have evolved on planet Earth.
Koala are angry, vicious little bastards. Smallpox just is. Sure, it's "just is" status in the wild causes some pretty nasty effects on us, but really, that's like a hailstone falling on your head. You live or you die, and you learn to get under cover in a certain type of weather. Koalas, though... just look at them beady little eyes. That's intent. Better to take them out now, just to be sure.
The last koala would be pretty useless without a mate :-)
If the gene sequence of smallpox is known and has been published, the bioterror risk already exists.
The root problem is that technology amplifies the capacity of humans to do both good and evil: good such as research that seeks beneficial knowledge from unlikely sources such as the smallpox virus, and evil such as synthesizing smallpox from scratch and setting off a new global pandemic. And the necessary cure entails bringing together the evolution of technologies and the evolution of social norms that restrain evil uses.
According to a recent episode of TWiV, there's a bunch of genetic information at the ends of the Variolla ?chromosomes? that is tough to sequence and that we don't know a lot about. The argument that we could create it de novo may not be accurate.
But if it is, that's more argument to keep it around I think - probably way easier for a terrorist to make it new in a lab than to sneak into high-security facility to steal it.