[nvmc]

I'd guess it is. Diseases are still organisms, and we try pretty hard not to let them go extinct.

[kevincrane]

What's the reason for keeping them though? Is it to make vaccines if they potentially come back or more sinister pre-emptive military reasons?

[krenoten]

We are always learning how to learn more. Destroying the specimens would destroy an opportunity to learn about an organism that has had a significant impact on our own species.

[epochwolf]

Research. Vaccines just in case we didn't get the all.