Researchers have re-created the extinct horsepox virus, which is closely related to smallpox, by cobbling together a patchwork of remaining pieces of DNA. The Canadian team's methods haven't been published but were reported in the news section of the journal Science on Thursday. Horsepox is harmless to humans, but scientists say this research means that smallpox may not be as extinct as previously thought.

"No question. If it's possible with horsepox, it's possible with smallpox," virologist Gerd Sutter of Ludwig Maximilians University in Munich, Germany, told Science. A World Health Organization report on the research says that recreating viruses this way takes little time, money or skill.

Why it matters: Smallpox plagued humans for thousands of years, before it was eradicated in 1977. The disease was horrific: before the smallpox vaccination was created, 1 out of 10 children in France and 1 in 7 children in Russia would die from the virus.

Not quite gone: After smallpox was eradicated, the remaining samples were supposed to be sent to two secure facilities where they could still be used for research, one in the US and one in Russia. A debate has raged over destroying those samples, because if the disease lingered hidden, those samples could help produce vaccines. It has long been a concern that terrorists might acquire the virus, either from one of the known labs, or from a different source. The WHO has measures in place should the virus re-emerge, though they say it is "impossible to assess the risk that this might happen."

Be prepared: It was concerns about potential re-emergence that led David Evans of the University of Alberta to re-create the horsepox virus. A press release from the company Tonix Pharmaceuticals states that this re-created horsepox is being used to develop a safer smallpox vaccine.

Evans argues that regardless of his research, someone would have eventually synthesized a pox virus. For years, researchers have known that modern techniques could hypothetically bring back smallpox. The polio virus was built from scratch in a lab in 2002, and in 2005 researchers re-created the 1918 flu virus. It should be noted that while creating the horsepox virus was simpler than many would like to believe, access to smallpox DNA is much more limited. "The world just needs to accept the fact that you can do this," Evans told Science. Now he hopes people will prepare.