NSC687852 current Centers for Disease Control and Prevention guidelines do not recommend either practice. However, the studies on which these recommendations are based were conducted in the pre-HAART era, evaluated small sample sizes, were not randomized and did not assess clinical outcomes. We evaluated HIV patients representative of most clinical settings in the developed world. Unfortunately, no clear, uniform and clinically significant benefit was identified with either immunization strategy. The use of a booster dose in our analysis, either with BMS 204352 standard dose or double dose, slightly improved immunogenicity with two of the three antigens evaluated compared to a single, standard dose of vaccine. This was most clearly evident in those without HIV RNA suppression at baseline. However, immunogenicity was suboptimal, irrespective of dosing strategy. Our work suggests that booster dosing with conventional influenza vaccine will not address the issue of poor immunogenicity in this vaccine hyporesponsive population. Although compelling, we do not believe that our results are robust enough to recommend booster dosing in those without HIV RNA suppression. There is little literature evaluating the efficacy of increased influenza vaccine antigen dose in HIV infected patients. In a sentinel work, Kroon et al evaluated the effect of double dose immunization in a cohort of HIV infected patients and concluded that this strategy was ineffective in augmenting antibody response. However, the comparison arm was not randomized, the sample size was small, and the study was conducted in the pre- HAART period. As such, the majority of participants were profoundly immune compromised. Therefore, the results may not be applicable to current HIV populations in the developed world. The majority of our study population was on antiretroviral therapy with virological suppression and CD4 counts well over 200 cells/ mL. Despite a small increase in immunogenicity with administration of a double dose, our analysis is consistent with the findings of Kroon et al. Although higher antigen doses could be assessed, widespread use of an increased antigen dose would create vaccine supply issues.