How long you need to rest after a course of interferon use is assessed according to the severity of each individual’s condition and treatment regimen. Interferon is clinically used for the treatment of viral infectious diseases, such as hepatitis B. A course of treatment usually takes about half a month, after which the patient’s number of hepatitis B virus replications, liver transaminase levels, and liver ultrasound will need to be evaluated to determine the need for a second course of treatment. For the treatment of AIDS and human papillomavirus infection, a one-month course of treatment is needed for about three consecutive months without interruption, and attention should be paid to evaluating the level of viral infection in the body after three months. When using interferon, it is important to note that patients who are allergic to the product should not use it, and it should not be used in patients with a history of myocardial infarction or other serious cardiovascular disease. Common adverse reactions are fever and fatigue. The use of interferon suggests that you can consult the infection department or dermatology and other related departments in regular hospitals.