It generally takes 2 weeks for the human body to gradually develop antibodies to the virus after infection with HIV. The “window period” is the period of time from when a person is infected with HIV to when antibodies can be detected in the peripheral blood, usually 2 weeks to 3 months. During this time, no antibodies to the virus can be detected in the blood, but the body is infectious. Only after the “window period” has passed will there be a sufficient amount of HIV antibodies in the blood to be detected. However, it should not be overlooked that different individuals have different immune responses to HIV, and the time of appearance of antibodies is also inconsistent, especially for people with recent high-risk behavior, a negative test result cannot be easily discharged from the infection, and should be checked again at intervals of 2 to 3 months.