After 2 weeks post-infection, the proliferation of CD4+ T lymphocytes was higher than that of CD8+ T lymphocytes; at 4 weeks post-infection, both lymphocyte types had a similar amount of proliferation; while at 6 and 8 weeks post-infection, the proliferation of CD8+ T lymphocytes exceeded that of CD4+ T lymphocytes [8]. Here, CD4 is linked to infection.