Hi 196~
Always go with a flamethrower.
You don’t want to get caught with inadequate firepower against an unknown species. Fire is the great equalizer.
Unless the thing you unearthed from the 15 thousands year old underground piece of ice from the north pole is a microscopic parasite that take months to show any symptoms and turn you into a zombie to spread. Then your just patient zero and we’re fucked as a specie.
Can’t take what we’ve made uninhabitable.
If the incubation is a few months, and it uses saliva to spread, then it’s too late. Unless you mean nuking all earth and surviving undergrounds à la Fallout.