Globally, the capacity of available CD4 instruments was sufficient to meet the demand of all people living with HIV/AIDS (PLWHA), irrespective of treatment status (4.62 theoretical tests per PLWHA in 2013 [median 7.33; interquartile range (IQR) 3.44–17.75; median absolute deviation (MAD) 4.35]). Here, CD4 is linked to AIDS.