<qa>  What is the sensitivity of the selenium supplementation to the already compromised group of patientsAll consenting patients with CD4 count between 400 and 650 mm3 will be selected because they are at similar immunological level and hence they will not be eligible to start ARV treatment at the study start. The study will look at the efficacy of selenium supplementation to this already compromised group of patients at a similar stage of the disease. 