Antibody and Cellular Immune Responses to 2011-2012 Seasonal Inactivated Influenza Vaccine in HIV-Infected and Uninfected Children and Young Adults
Methods: 11 HIV-infected subjects and 7 controls received one dose of 2011-2012 IIV3. Plasma and cells were frozen pre-vaccination (T1) and 2-4 weeks post-vaccination (T2). At each timepoint, hemagglutination inhibition (HAI) was done for all 3 vaccine strains; antibody avidity (AI), B-cell memory (IgG ELISPOT), T cell response (IFNγ and IL-2 ELISPOT) for pH1N1; and B- and T-cell phenotypes (flow cytometry). All subjects were surveyed on vaccination history during the 2010-2011 season and whether they were vaccinated prior to the 2010-2011 season.
Results: Average CD4 count of HIV-infected was 555 (median 590), and 9/11 (82%) were on cART. There was no significant difference between the cohorts in HAI at either timepoint, or in rates of seroprotection/seroconversion for any viruses. Individuals in both cohorts who had not been vaccinated in prior years had a higher fold-raise (FR) in HAI to pH1N1 but not to H3 or B viruses (p=0.008). The median AI for pH1N1 was higher at baseline for HIV-infected vs. controls, 0.32 and 0.19 (p=0.003) respectively. The AI was not different at T2 nor was the change from T1 to T2. T cell ELISPOT results were similar between cohorts. IgG ELISPOT in HIV-infected vs. controls showed no difference in numbers at T1 (4.5 vs. 4, p=NS); a trend difference at T2 (6.8 vs. 23.5, p=0.07); and significant differences in the absolute change and FR from T1 to T2 (2 vs. 18.5, p=0.04; 0.9 vs. 5.22, p=0.04). History of prior influenza vaccine was associated with a significant difference in IgG ELISPOT FR (2.44 for vaccinated vs. 0 for unvaccinated, p=0.05) for HIV-infected, but not for controls (2.5 vaccinated vs. 15.3 unvaccinated, p=NS). Flow cytometry revealed higher percent of tissue-like (7.8% vs. 4.1%, p=0.03) and immature (25.6% vs. 8.9%, p=0.02) B cells in HIV-infected vs. controls at baseline.
Conclusion: Despite high cART uptake and high CD4 count, the HIV-infected cohort showed significantly lower memory B cell responses compared with controls. A history of influenza vaccine was advantageous to HIV-infected but not controls in developing a B cell IgG response.
Sanofi-Pasteur: Support for an Investigator-Initiated protocol, Research support
L. Pyle, None
A. Weinberg, Sanofi-Pasteur: Support for an Investigator-Initiated protocol, Research support
MedImmune: Grant Investigator, Research grant