CD4 and infection: (D) RhIVBG505 and VSVMLV-E viremia (log10 RNA copies/ml of plasma, upper rows) and blood CD4+ T-cell proportion (% of CD3+ cells, lower rows) in A1Ifnar-/- mice following infection with RhIVBG505 on day 0 and day 28 (left panels), VSVMLV-E on day 0 and RhIVBG505 day 28 (center panels) or RhIVBG505 on day 0 and VSVMLV-E day 28 (right panels).