On May 5, 2014, it was announced John Krasinski would direct the film, with Krasinski, Anna Kendrick, Margo Martindale and Richard Jenkins joining the cast.
Epstein-Barr virus (EBV) is a ubiquitous herpesvirus spread by human contact with no know environmental reservoir. Antibodies are detected in 90 to 95% of adults worldwide. EBV infection is subclinical in 90% of children.
Infection with the Epstein-Barr virus (EBV) is an important risk factor for Burkitt lymphoma in some parts of Africa. In developed countries such as the United States, EBV is more often linked with lymphomas in people also infected with HIV, the virus that causes AIDS.