Using the Danish CD4 proxy had a minimal effect on the estimates of the number of new infections and PLHIV, but resulted in a longer estimated time from infection to diagnosis (3.0 years, interquartile range: 1.5–5.7), a higher number of undiagnosed infections (520 [95%CI: 411–627]), and thus a larger undiagnosed fraction (10.2% [8.3–12.1]) (Table 2). This evidence concerns the gene CD4 and infection.