If a person with HIV infection is asymptomatic (has no symptoms of other infections—“AIDS defining conditions”) then with a normal CD4 level as you report for your brother, then Antiretroviral therapy should not be given. The doctor gave you the correct advice. HIV infection slowly destroys the ability of the body to fight disease, and when the body cannot resist other common infection it is called AIDS. The persons with AIDS fall seriously ill with infections and this is what threatens the life of AIDS patients. This loss of immunity manifests as a low CD4 count. ART (Antiretroviral Therapy) therefore is needed when the immune response of the body is much reduced. The reason for this in simple terms is that these drugs act by increasing the CD4 count to a higher level and by doing this allow the body to fight other infections.It is more difficult to decide when ART should be started. All the current recommendations agree that ART should be started when HIV related infections start regardless of the CD4 count. However if they are no infections and the CD4 cell count is high then there is no advantage to starting ART because the patient does not benefit in any way. An additional problem is that resistance to ART develops easily and giving the ART when it is not essential does not give any benefit and has the high potential harm of resistance appearing so that when ART is actually needed, resistance may have already developed to the first line ART. Earlier it was recommended that ART should be started when the count falls below 200, the current WHO (and other) authorities recommend that ART is started if the CD4 count falls below 350.In either case it is not in the interest of your brother to initiate ART at this time. When the time comes when these drugs are needed please do not hesitate to initiate their use and pay special attention to the fact that he must follow the treatment regime very, very strictly and never miss a dose to avoid (or delay) developing resistance. At this point life style changes are more important than medicines. A regular life with adequate rest and exercise and nutrition along with taking care to get all illnesses treated no matter how mild will keep him healthy for a long time.