Should the remaining smallpox viruses be destroyed?

Inspired by the virus revival post from yesterday.

There is still an ongoing debate as to whether the remaining smallpox virus samples should be permanently destroyed, or retained. One storage unit is in Russia, the other in the USA.

Those in favour of destruction fear that the virus could be re-introduced into the world by accident or due to bio-terrorism, and that the storage is unneccessary as the disease is eradicated.

Those against destruction say that the virus is still necessary for research purposes, and for the development of antiviral drugs.

This is another debate I am on the fence on, I see both sides and cannot make a decision either way.