Season 4 (Infections)

Main

 * Chloe Grace Moretz - Nikki Alexis
 * Rutina Wesley - Kaya Dutch
 * Leigh Allyn Baker - Sarah Walters
 * Dove Cameron - Melanie
 * Josh Duhamel - Gus
 * Ansel Elgort - Russel
 * Emily Kinney - Danni Bleu
 * Bethany Anne Lind - Quin
 * Billie Lourd - Jane
 * Melanie Martinez - MacKenzie Jameson
 * Jennette McCurdy - Abby Walters
 * Dylan O'Brien - Jake
 * Carlos PenaVega - Mikel
 * Mary Scheer - Diane

Guest

 * Madison Lintz
 * Alexa Nicolas

Deaths
TBA

Trivia

 * Many changes were made to the main cast
 * Though only making their first appearance, Chloe Grace Moretz, Josh Duhamel and Ansel Elgort were added to the main cast.
 * Nina Dobrev, Jensen Ackles, Neil Patrick Harris, James Allen McCune, Tanner Holland and Ving Rhames were removed from the main cast following their character deaths.
 * Madison Lintz and Alexa Nicolas were added to the guest cast.