It’s not yet certain which animals are the natural carriers. But, based on the available evidence, it is thought to be ...

An FDA-approved vaccine for smallpox and mpox is effective but causes side effects. The other requires multiple doses. An experimental single-dose vaccine uses the horsepox virus to harness the ...

Two outbreaks of the disease, which is caused by a virus in the same family as the one that causes smallpox, were discovered ...