CD4 and AIDS: We next tested whether the contribution of an individual HLA class I allele to the total HIV-1-specific CD8+ T cell response in primary infection is associated with the HR for that allele in progression to four HIV-1 disease outcomes (CD4 <200, AIDS 1987, AIDS 1993, and death), using data from four HIV-1 cohorts (MACS, MHCS, SFCCC, and ALIVE) [27–30].