<prompt> Window period in HIV is defined asPeriod between onset of infection and clinically detectable level of antibodiesPeriod between infection and appearance of symptomsTime between HIV positivity to AIDSCD4 count 200  <response>: Window period The time period between primary infection and detection of antibodies is called window period.Traditional methods used in the diagnosis of HIV such as ELISA and western blot are based on the detection of these antibodies i.e., these tests become positive once the antibodies appear in the blood.However, the recent methods used in the diagnosis of HIV are based on the detection of virus or virus particles not antibodies.Virus or the virus particles appear early in the blood than antibodies so the newer methods have considerably reduced the period between the infection and the diagnosis i.e., they have reduced the window periodMethods of the detection Window periodAntibody detection ELISA western blot 22 daysp24 Antigen 16 daysNucleic detection 12 days 