n 1975, a Sino-Soviet border conflict escalates into worldwide biological warfare, which kills most of the world's population. U.S. Army Col. Robert Neville, M.D., is a scientist based in Los Angeles. As he begins to succumb to the plague, he injects himself with an experimental vaccine, rendering himself immune.
By 1977, Neville believes he is the plague's only immune survivor. Struggling to maintain his sanity, he spends his days patrolling the now-desolate Los Angeles, hunting and killing members of "the Family", a cult of plague victims who were turned into nocturnal albino mutants. The Family seeks to destroy all technology and kill Neville, who has become a symbol of the science they blame for humanity's downfall. At night, living atop a fortified apartment building equipped with an arsenal of weaponry, Neville is a prisoner in his own home.
https://en.wikipedia.org/wiki/The_Omega_Man