tetano
Editor, Senior Moderator
AIDS. 2012 Oct 1. [Epub ahead of print]
Efficacy and immunogenicity of influenza vaccine in HIV-infected children: A randomized, double-blind, placebo controlled trial.
Madhi SA, Dittmer S, Kuwanda L, Venter M, Cassim H, Lazarus E, Thomas T, Liberty A, Treurnich F, Cutland CL, Weinberg A, Violari A.
Source
aNational Institute of Communicable Diseases- Division of National Health Laboratory Service, Sandringham, South Africa bDepartment of Science and Technology/ National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Johannesburg, South Africa; cMedical Research Council: Respiratory & Meningeal Pathogens Research Unit, University of the Witwatersrand, Johannesburg, South Africa dPerinatal HIV Research Unit, University of the Witwatersrand, Johannesburg, South Africa eDepartment of Pediatrics, Medicine and Pathology, University of Colorado, Anschutz Medical Campus, Colorado, USA.
Abstract
BACKGROUND:: HIV-infected children are at heightened risk for severe influenza illness; however, there is no study on the efficacy or effectiveness of influenza vaccine in these children. We evaluated the safety, immunogenicity and efficacy of non-adjuvanted, trivalent inactivated influenza vaccine (TIV) against confirmed seasonal-influenza virus illness in HIV-infected children. METHODS:: A double-blind, placebo-controlled trial was undertaken in Johannesburg in 2009. 410 children were randomized to two doses of TIV or placebo one month apart. Nasopharyngeal aspirates obtained at respiratory illness visits were tested by influenza-specific RT-PCR. Vaccine immunogenicity was evaluated by hemagglutination inhibition assay (HAI). Influenza isolates were sequenced and evaluated in maximum likelihood phylogenetic analysis. RESULTS:: Participants median age was 23.8 months, median CD4+ 33.5% and 92% were on antiretroviral therapy. Among children receiving both doses of vaccine/placebo, confirmed seasonal-influenza illness occurred in 13 (all H3N2) of 205 TIV-recipients and 17 (15 H3N2 and 2 influenza B) of 200 placebo-recipients; vaccine efficacy of 17.7% (95%CI < 0 to 62.4%). The proportion of TIV-recipients who sero-converted post second-dose against vaccine-strains of H1N1, H3N2 and influenza B were 47.5%, 50.0% and 40.0%, compared to 4.7%, 11.6% and 0%, respectively among placebo-recipients. There were no TIV-related serious adverse events. Sequence analysis of wild-type H3N2 strains indicated drift from the H3N2 vaccine-strain. CONCLUSION:: Poor immunogenicity of TIV, coupled with drift of circulating H3N2 wild-type compared to vaccine strain, may explain the lack of efficacy of TIV in young HIV-infected children. Alternate TIV vaccine schedules or formulations warrant evaluation for efficacy in HIV-infected children.
PMID:
23032417
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/23032417
Efficacy and immunogenicity of influenza vaccine in HIV-infected children: A randomized, double-blind, placebo controlled trial.
Madhi SA, Dittmer S, Kuwanda L, Venter M, Cassim H, Lazarus E, Thomas T, Liberty A, Treurnich F, Cutland CL, Weinberg A, Violari A.
Source
aNational Institute of Communicable Diseases- Division of National Health Laboratory Service, Sandringham, South Africa bDepartment of Science and Technology/ National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Johannesburg, South Africa; cMedical Research Council: Respiratory & Meningeal Pathogens Research Unit, University of the Witwatersrand, Johannesburg, South Africa dPerinatal HIV Research Unit, University of the Witwatersrand, Johannesburg, South Africa eDepartment of Pediatrics, Medicine and Pathology, University of Colorado, Anschutz Medical Campus, Colorado, USA.
Abstract
BACKGROUND:: HIV-infected children are at heightened risk for severe influenza illness; however, there is no study on the efficacy or effectiveness of influenza vaccine in these children. We evaluated the safety, immunogenicity and efficacy of non-adjuvanted, trivalent inactivated influenza vaccine (TIV) against confirmed seasonal-influenza virus illness in HIV-infected children. METHODS:: A double-blind, placebo-controlled trial was undertaken in Johannesburg in 2009. 410 children were randomized to two doses of TIV or placebo one month apart. Nasopharyngeal aspirates obtained at respiratory illness visits were tested by influenza-specific RT-PCR. Vaccine immunogenicity was evaluated by hemagglutination inhibition assay (HAI). Influenza isolates were sequenced and evaluated in maximum likelihood phylogenetic analysis. RESULTS:: Participants median age was 23.8 months, median CD4+ 33.5% and 92% were on antiretroviral therapy. Among children receiving both doses of vaccine/placebo, confirmed seasonal-influenza illness occurred in 13 (all H3N2) of 205 TIV-recipients and 17 (15 H3N2 and 2 influenza B) of 200 placebo-recipients; vaccine efficacy of 17.7% (95%CI < 0 to 62.4%). The proportion of TIV-recipients who sero-converted post second-dose against vaccine-strains of H1N1, H3N2 and influenza B were 47.5%, 50.0% and 40.0%, compared to 4.7%, 11.6% and 0%, respectively among placebo-recipients. There were no TIV-related serious adverse events. Sequence analysis of wild-type H3N2 strains indicated drift from the H3N2 vaccine-strain. CONCLUSION:: Poor immunogenicity of TIV, coupled with drift of circulating H3N2 wild-type compared to vaccine strain, may explain the lack of efficacy of TIV in young HIV-infected children. Alternate TIV vaccine schedules or formulations warrant evaluation for efficacy in HIV-infected children.
PMID:
23032417
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/23032417