It is possible that blood donations during the window period of HIV may not be detected. The time period between HIV infection and antibody production, called the window period, is usually about 2-3 weeks. With the current advances in testing methods, the window period has been shortened, and in some places it may only be about a week. For people at high risk, blood donation is not recommended during the window period because of the risk of transmitting HIV to other patients. It is generally recommended that after the window period has passed and the test is negative for HIV antibodies, it is then recommended to go to the local blood bank to donate blood.