What is involved in HIV testing?
Most HIV tests actually detect the presence of HIV antibodies, not the virus itself. Antibodies are proteins that are produced in the blood to fight infection. It takes the immune system time to identify the virus and begin producing antibodies. Most people will develop detectable antibodies within two to eight weeks (the average is 25 days) of contracting the virus. Ninety-seven percent will develop antibodies in the first three months following the time of their infection. In very rare cases, it can take up to six months to develop antibodies to HIV. The time between when a person is infected and when the body produces enough antibodies against HIV to be detected is called the window period. Even if someone tests negative for HIV antibodies, they can still transmit the virus.
