Another animal that seems likely to be a candidate for xenotransplantation is the baboon because it is genetically very similar to human. This decreases the likelihood of rejection. In fact, baboon-to-human transplants have been attempted, The Spanish Influenza of 1918 was the deadliest pandemic in modern history. The virus, now thought to have come from a mutation of wild bird flu, infected 20 to 40 percent of the world’s population and killed 50 million people worldwide. The virus touched all comers of the glode, including populations on remote islands, main continents, and the Arctic.