CD4 and infection: In bivariate analyses, the following factors emerged as protective factors against infection by oncogenic virus: older age (36.1 vs 39.2 years, P = .0001; crude OR: 4.5), retirement (5% vs 14.3%; P = .017; crude OR: 0.32), higher CD4 cell count (675.5 vs 828.7 cells/μL; P = .04; crude OR: 1), and viral load <50 copies/mL (70.9 vs 85.4%, P = .047; crude OR: 0.47).