CD4 cell counts are used, together with the viral load test, to get a completepicture of how the immune system is fighting the virus. The amount of CD4 cellsand viral load levels will also guide a patient and their doctor in decidingwhen to start antiviral medication. The goals are to keep CD4 count high andviral load low. Therefore, monitoring CD4 counts and HIV-1 viral load levelsbefore and during treatment will help a doctor assess how well their patientis responding to their prescribed therapy.