Smallpox virus killed millions of people until a public health campaign to eliminate it globally was successful in the 1970's. We have two sources of the virus in deep freeze, and scientists debate whether or not to destroy these two last collections because of the risk of bioterrorism - we no longer vaccinate for this virus. Currently, attempts to eradicate another deadly virus, polio virus, from the planet are underway. However an unexpected use for polio virus has been discovered. Go to Polio and comment on this treatment or if you think humans should intentionally eliminate deadly viruses from the planet.