Abstract: Described herein are compositions for treating or preventing a viral infection comprising bacteriophages that bind to the virus and block or inhibit viral entry into a host cell. Bacteriophage libraries may be screened to identify bacteriophages that bind to a virus of interest, and the identified bacteriophages may be used to treat or prevent an infection caused by the virus of interest. Also described herein are methods of treating or preventing a viral infection by administering a bacteriophage composition to a subject in vivo or to a surface in vitro. The bacteriophages in the composition may bind to the virus and inhibit viral entry into a host cell, thereby reducing the infectivity of the virus. Reducing the infectivity of the virus may treat or prevent the viral infection.