The window period generally refers to the period of time between infection with the virus and the detection of the appropriate antibodies. Since antibodies cannot be detected, the window period is clinically undiagnosed, but there is often a certain amount of virus in the blood, and infection has actually occurred, only that it is not yet detected in the blood. Patients in the window period are somewhat infectious, for example, blood in the window period of AIDS may be infected with AIDS if there is a history of cross-contact. During the window period, patients may also develop some non-specific signs and symptoms, for example, patients in the window period of AIDS may have symptoms such as low fever, swollen lymph nodes, weakness, diarrhea, joint pain, etc. If one is suspected to be in the window period of a disease, what needs to be done is regular testing, usually 2-3 times in a row, until the maximum incubation period.