The Vaccine Race

An invisible world of astonishing complexity is all around you. A world so small you can't see it with the naked eye. A world so crowded that its population staggers the mind. A world in which you participate every day—often without even knowing it. The inhabitants of this world are trillions of bacteria, viruses, fungi, and other organisms, collectively known as microbes. Hundreds of thousands could fit on the period at the end of this sentence. And many play a powerful role in your life, from the bacteria in your stomach that help you digest food to the pathogens that make you sick.

The fifth season of the science fiction television series The X-Files commenced airing on the Fox network in the United States on November 2, 1997, concluding on the same channel on May 17, 1998, and contained 20 episodes. The season was the last in Vancouver, Canada; subsequent episodes would be shot in Los Angeles, California. In addition, this was the first season of the show where the course of the story was planned in advance, due to the 1998 The X-Files feature film being filmed before it, but schedule to be released after it aired.

The fifth season of the series focused heavily on FBI federal agents Fox Mulder's (David Duchovny) loss of faith in the existence of extraterrestrials and his partner, Dana Scully's (Gillian Anderson), resurgence of health following her bout with cancer. New characters were also introduced, including agents Jeffrey Spender (Chris Owens) and Diana Fowley (Mimi Rogers) and the psychic Gibson Praise (Jeff Gulka). The finale, "The End", led up to both the 1998 film and the sixth season premiere "The Beginning".