Conjugate And Polysaccharide Vaccines Compared With Polysaccharide Vaccine In Hiv-Infected Adults

Overview

Randomised study comparing two pneumococcal vaccination strategies in HIV-infected adults with moderate immunossupression (CD4 between 200 and 500 cells/uL and viral load under 5logs), one with conjugated heptavalent vaccine(Prevenar, Wyeth-Lederle) followed by polysaccharide vaccine 4 weeks after (Aventis-Pasteur), and two with one dose of polysaccharide vaccine. Determination of secondary effects related to both vaccines and determination of antibody concentration (ELISA) and avidity (ELISA with thiocyanate) and opsonophagocytosis killing activity against the seven serotypes included in the heptavalent vaccine before vaccination, at 4 weeks, at 8 weeks, at48 weeks and 96 weeks. A sample of 220 HIV-infected adults (110 in each group) will be needed to detect differences of 10% for a type I error o 5% for a limited population of 2500 HIV-infected adults. The main hypothesis are :the immunogenicity of pneumococcal vaccination with conjugate and polysaccharide vaccines is superior to immunogenicity induced by polysaccharide vaccination alone(antibody concentration), the avidity and opsonophagocytosis induced by two vaccines is better than the one after polysaccharide vaccine alone, both vaccinations are safe.

Randomised study comparing two pneumococcal vaccination strategies in HIV-infected adults with moderate immunossupression (CD4 between 200 and 500 cells/uL and viral load under 5logs), one with conjugated heptavalent vaccine(Prevenar, Wyeth-Lederle) followed by polysaccharide vaccine 4 weeks after (Aventis-Pasteur), and two with one dose of polysaccharide vaccine. A sample of 220 HIV-infected adults will be randomised to receive twe strategy one(110 patients) one dose of heptavalent conjugated vaccine at day 0 and one dose of polysaccharide vaccine at week 4 (in deltoid muscle); or strategy two (110 patients) one dose of polysaccharide vaccine at day 0. Secondary effects to the vaccines will be evaluated by phone interview 3 days after vaccinations. Blood samples will be taken at day 0(before the first vaccine), at week 4 before the polysaccharide in the group one, and 4 weeks after the polysaccharide in the group two) and at week 8 in the group one, and at weeks 48 and 96 in both groups Antibody concentration , avidity, and opsonophagocytic killing activity will be measured in all the samples for serotypes 4,14,19F,23F,6B,18C,9V. Antibody concentration , avidity, and opsonophagocytic killing activity will be compared between both vaccine groups, and between prevaccination and at 4,8, 48 and 96 weeks of vaccination. Risk factors associated to good antibody response (antibody duplication and antibody duplication plus achieve a level above 1ug/ml)will be measured at 8, 48 and96 weeks.