Hi docs I'm posting questions on hiv window period and I'm getting different opinions but according to me the window period is 4 to 6 weeks rapid tests but maximum it may take 3 months as the newer tests detects antibody very early and effective and this is according to WHO, CDC and NACO guidelines the window period may be prolonged in only 4 cases that are 1.patient taking post exposure prophylaxis for hiv. 2.treatment for hep c 3.chemotherapy.4.immunodeficiency disorders like hypogammaglobulinemia if the person don't come in the above cases the maximum window period is only 3 months and the test results are 100% conclusive. Please don't say 6 months, 9 months, 1 year,2 year as the person becomes panic and goes to frequent testing. It is 100% sure that if you are negative at 3 months after exposure you are negative no further test should be taken and waste money. Ref from WHO, CDC,NACO, Aids Vancouver, the body. Com, Harrison manual and others.