CD4 and influenza: We found some degree of immune reconstitution in the frequency of activated influenza-specific CD4+ T-cells expressing CD154 in HIV-infected patients following 6 months on HAART (0.0%[0.0–0.03] vs. 0.03%[0.0–0.06]; p = 0.03), however, the frequency was still lower than HIV-uninfected individuals (0.03%[0.0–0.06] vs. 0.1%[0.06–0.2]; p = 0.001) (Figure 2B).