Antidote Man

An old man dying of cancer has just become the perfect test subject for an alien race seeking to exterminate mankind. Their goal: create a mutant viral strain impervious to cures. As part of their experiments, the aliens have perfected brain transplants, allowing them to place the old man's brain in a new body, infect it with every possible virus, and test various antidotes. By the end, the man's blood carries the antidote to every virus and cancer known to humans.

Sent back to Earth in a shuttle, the old man sets about collecting virus samples from Africa. Meanwhile, another human scientist onboard the alien ship releases an airborne virus that kills everyone - alien and human - on the ship. Left on Earth, the old man faces a world of corrupt politicians, drug companies, and rogue federal agents - and they all want samples of his blood.