In general, for all MSMS with initial CD4 count of 200 cells/μl or above, CRF55_01B infections caused a significantly higher increasing rate of plasma HIV RNA load than CRF07_BC infections (2.0 log10 copies/ml [95%CI 1.1–2.9] vs. 0.7 log10 copies/ml [95%CI 0.5–0.9], P < 0.01), while not significantly different from infection with CRF01_AE (1.4 log10 copies/ml [95%CI 0.8–2.0], P = 0.324) (Table 3). This evidence concerns the gene CD4 and infection.