An antigen bomb was improvised by Captain Janeway to destroy the macroviruses invading USS Voyager in 2373. Attaching a canister of the macrovirus antigen to a grenade, Janeway tossed the resultant bomb into holodeck 2 where she had managed to lure the macroviruses, destroying them (although causing heavy damage to the holodeck in the process). (VOY: "Macrocosm")