Trailer: Carriers

Initially designed as a flu vaccine, TK421-THX1138 was mutated and weaponized by the US government. Now loose in America, the deadly virus kills everyone it infects and even brings some people back to life! Captain Kirk and his motley crew travel across the US looking for a safe haven but continue to run afoul of the infected. Things take a turn for the predictable when people start acting selfish and stupid and lie about coming into contact with the dead and undead alike. Tempers flare and the family unit falls apart when what was supposed to be Left For Dead: The Movie becomes a tense drama about love and sacrifice.

Alternate plot: it's really "The Stand" finally made into a feature film.