David Duchovny Dr. Ira Kane Julianne Moore Dr. Allison Reed, CDC Orlando Jones Prof. Harry Phineas Block Seann William Scott Wayne Grey Ted Levine General Russell Woodman Ty Burrell Colonel Flemming Ethan Suplee Deke Michael Bower Danny Dan Aykroyd Governor Lewis Gregory Itzin Cartwright Pat Kilbane Officer Johnson Sarah Silverman Denise Michelle Wolff Carla Katharine Towne Nadine Stephanie Hodge Jill Mason John Cho Student Steven Gilborn Judge Guilder Wayne Duvall Dr. Paulson Kyle Gass Officer Drake Jerry Trainor Tommy Jennifer Savidge Clare Wendy Braun Nurse Tate Michael Chapman Sheriff Long Mary Pat Gleason Customer Andrew Bowen Road Worker Chris Wylde Student Tom Woodruff Jr. Lead Primate Creature (uncredited)