Figure 2

Anti-H1N1 antibody levels detected by microbead-based array assay before and within 1–5 months after receiving the ASO3-adjuvanted A/California/07/09 H1N1 influenza HA vaccine for 80 HIV-infected individuals (a). The dotted line at MFI 125 separates individuals with pre-existing anti-H1N1 antibodies from those without. Comparison of the age distribution for vaccinated individuals categorized as non-responders, responders or responders with pre-existing antibodies against A/California/07/09 H1N1 HA (b). Lines within groups show the group median with IQR and the p value indicating probability of no significant difference between groups is shown above lines spanning the groups being compared.