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Medical experts are deciding if they want to keep smallpox alive. The question is whether to destroy the last known samples of the deadly viruses, which are held in labs in the United States and Russia. Some countries want to get rid of them so they can't be used as weapons, or get accidentally released. The U.S. government wants to keep these samples, saying they are still needed to develop new therapies and vaccines.
It turns out that valuable samples of other dangerous microbes get destroyed all the time. Here's NPR's Nell Greenfieldboyce.
NELL GREENFIELDBOYCE: Anne Vidaver is a plant pathologist at the University of Nebraska in Lincoln. She recently spent a few years researching one particular kind of bacteria that causes a slime disease in grasses. It makes the grasses toxic to grazing animals, like sheep.
But then the government decided this disease had potential as a bioweapon. So it was added to a special list of pathogens that could potentially be used by terrorists against crops or people. Once it became a so-called select agent, all research had to be carefully restricted. So that meant the end to business as usual for Anne Vidaver's slime disease work.
Dr. ANNE VIDAVER (Plant Pathologist, University of Nebraska): Essentially, I had to either receive special permission to work with it, or destroy it.
GREENFIELDBOYCE: Getting this special permission wouldn't be easy. It would mean things like putting in new lab security, and doing background checks of personnel.
Dr. VIDAVER: It would have required an enormous amount of funding and time. That did not work out.
GREENFIELDBOYCE: So she took her slime disease cultures and destroyed them.
Now, she says, in this case, there are duplicate samples in a secure government lab in Fort Detrick. But Vidaver says she knows of colleagues in similar situations who had to destroy unique samples of dangerous microbes - meaning, they were lost to science.
That kind of loss worries Michael Imperiale.
Professor MICHAEL IMPERIALE (Microbiologist, University of Michigan): Some of these microbes might be valuable down the line.
GREENFIELDBOYCE: Imperiale is a microbiologist at the University of Michigan in Ann Arbor. He says scientists have historically collected different strains of microbes because they're useful. For example, large collections of influenza viruses helped researchers understand the pandemic flu strain that emerged a couple of years ago. Microbe collections can also be crucial for developing new drugs or vaccines.
He says he started to hear about scientists destroying microbes in the wake of 9/11, and the anthrax attacks that soon followed. That was when the government started imposing its new restrictions on research into microbes that could potentially be used by terrorists.
To get a sense of how many collections might have been lost, Imperiale recently sent a survey to microbiologists across the country.
Prof. IMPERIALE: Although we know that the 12 or 13 or 14 institutions from whom we heard destroyed what they had, we don't know how many others there were out there. So we don't have a good - we can't say well, X-percent of the strains were destroyed, or something like that.
GREENFIELDBOYCE: In an emailed statement, the Centers for Disease Control and Prevention told NPR that the agency does try to help scientists transfer microbes to labs that can legally hold them. It noted that multiple collections have been transferred directly to the CDC. And in many cases, the agency even helped pay for the shipping.
But another researcher, who worked on the recent survey, reports that microbe destruction is still happening. Arturo Casadevall is a scientist at the Albert Einstein College of Medicine.
Dr. ARTURO CASADEVALL (Albert Einstein College of Medicine): They're going to say to you that yes, there are mechanisms in place for the transfer of these things. But what is not recognized is that these mechanisms are complex. They require a lot of energy, and they require the person to put a lot of energy into doing so.
GREENFIELDBOYCE: He says most doctors and researchers just don't have the time.
Dr. CASADEVALL: Let's say that at any hospital, you recover from a patient one of these agents. You have only a few days by which to either send it to a collection, or to destroy it.
GREENFIELDBOYCE: He says it can be hard to find a collection that actually wants your microbe. And even then, you can't just drop it in a mailbox. So the easiest way to comply with the law is destruction.
Nell Greenfieldboyce, NPR News.