CD4 and infection: CD4 cells belong to a group of lymphocytes, also called CD4+ T cells, fighting infections within the human body.27 Its count may be influenced by sex,28,29 onset or existence of a co-infection, oral contraceptive pills, smoking habit and sleep patterns.28 A study in South Africa showed that females and younger patients had a better immune response to treatment.30In this study, an interesting observation was made in the variability of CD4 count.