The National Health and Wellness Commission has released the “Pneumonia Treatment Protocol for Novel Coronavirus Infection (Trial Version 5)”. The Trial Version 5 Treatment Protocol makes it clear that the source of infection seen so far is mainly patients with novel coronavirus infection. Asymptomatic infected persons may also be a source of infection. Knowing when an infected person can transmit the virus to others is critical to control efforts, and the period of transmission of new coronavirus pneumonia needs to be determined based on detailed medical information of the infected person. According to recent reports, people infected with NCCP may become infectious before the onset of overt symptoms.