Long-Term Immunogenicity after One and Two Doses of a Monovalent MF59-Adjuvanted A/H1N1 Influenza Virus Vaccine Coadministered with the Seasonal 2009-2010 Nonadjuvanted Influenza Virus Vaccine in HIV-Infected Children, Adolescents, and Young Adults in a Randomized Controlled Trial

Abstract

Few data are available on the safety and long-term immunogenicity of A/H1N1 pandemic influenza vaccines for HIV-infected pediatric patients. We performed a randomized controlled trial to evaluate the safety and long-term immunogenicity of 1 versus 2 doses of the 2009 monovalent pandemic influenza A/H1N1 MF59-adjuvanted vaccine (PV) coadministered with the seasonal 2009-2010 trivalent nonadjuvanted influenza vaccine (SV) to HIV-infected children, adolescents, and young adults. A total of 66 HIV-infected patients aged 9 to 26 years were randomized to receive one (group 1) or two (group 2) doses of PV coadministered with 1 dose of SV. The main outcome was the seroconversion rate for PV at 1 month. Secondary outcomes were the geometric mean titer ratios and the seroprotection rates at 1 month for all vaccines, seroconversion rates at 1 month for SV, and longitudinal changes of antibody titers (ABTs) at 1, 2, 6, and 12 months for all vaccines. Groups 1 and 2 had similar CD4 counts and HIV RNA levels during the study. The seroconversion rate for PV was 100% at 1 month in both groups. ABTs for PV were high during the first 6 months and declined below seroprotection levels thereafter. Longitudinal changes in ABTs were similar in groups 1 and 2 for both PV and SV. The side effects of vaccination were mild and mostly local. In HIV-infected children, adolescents, and young adults, the immune response triggered by a single dose of PV was similar to that obtained with a double dose and was associated with long-term antibody response.

HIV virological suppression influences response to the AS03‐adjuvanted monovalent pandemic influenza A H1N1 vaccine in HIV‐infected children

“…17 Other studies on the immunogenicity of the mf59-and AS03-adjuvanted pH1N1 vaccine in children with HIV, however, reported higher seroconversion and seroprotection rates. 16,18,21 Seven children (29%) had protective antibody titres to pH1N1 at baseline, reflecting a trend seen in other pH1N1 immunogenicity studies, and signifying either cross-reactivity with antibody to seasonal influenza or previous infection. 6 In contrast to other studies in adults and children with HIV, the booster dose of vaccine did not appear to increase either the overall seroconversion rate or the magnitude of the immunological response in our study participants.…”

“…The seroconversion rates of 75% after the prime dose and 71% after the booster dose compared favourably with rates reported for the unadjuvanted vaccine in Thai children, and the mf59‐adjuvanted monovalent pH1N1 vaccine in Italian children with HIV . Other studies on the immunogenicity of the mf59‐ and AS03‐adjuvanted pH1N1 vaccine in children with HIV, however, reported higher seroconversion and seroprotection rates …”

“…Studies on the immunogenicity of pH1N1 vaccination among HIV‐positive adults have demonstrated better immunogenicity with adjuvanted vaccines, and a more sustained response after prime and booster vaccinations . Similar data have emerged from studies on both the unadjuvanted and the mf59‐adjuvanted pH1N1 vaccine in HIV‐infected children . In July 2009, shortly after the pandemic was declared, a Strategic Advisory Group of Experts on Vaccination strongly advocated the use of a vaccine against pH1N1 among vulnerable groups including people living with HIV .…”

“…6,14,15 Similar data have emerged from studies on both the unadjuvanted and the mf59-adjuvanted pH1N1 vaccine in HIV-infected children. [16][17][18][19] In July 2009, shortly after the pandemic was declared, a Strategic Advisory Group of Experts on Vaccination strongly advocated the use of a vaccine against pH1N1 among vulnerable groups including people living with HIV. 20 Large-scale vaccination against pH1N1 was undertaken in Ireland using an inactivated, splitvirion AS03 (squalene oil emulsion) adjuvanted vaccine (Pandemrix).…”

Phase II trial in adults of concurrent or sequential 2009 pandemic H1N1 and 2009–2010 seasonal trivalent influenza vaccinations

“…Less than 1% experienced severe systemic reactions related to vaccine. The favorable safety profile following the administration of 2009-H1N1 vaccine in adults is consistent with the findings in multiple trials of adjuvanted and unadjuvanted 2009-H1N1 tested as a single vaccine(9,11,12,21,22,23-31) or concurrently or sequentially administered with V3(27-31) and during surveillance during a mass vaccination campaign.…”