IMHO, he is not going to give new virus to the whole earth, the virus already exists hence freely speading by itself from host to host. The idea is to speed up

IMHO, he is not going to give new virus to the whole earth, the virus already exists hence freely speading by itself from host to host. The idea is to speed up spreading of "good" virus to preempt spreading of a bad one and finally make the last to extinct.