The Encyclopedia Of Science Fiction:

Under his own name, King has written two [further] novels which are SF by any measure (though both encorporate elements from other genres). The earlier and better is The Stand, a long and intelligent story of the holocaust and after in the USA, beginning with the accidental release of a germ-warfare virus by the US military; in the second half of the book a supernatural struggle between powers of light and darkness weakens the impact from an SF point of view, but the novel remains a very superior example of its genre, clearly owing something to George R Stewarts Earth Abides (1949), but not imitative of it.