Μελέτη της προστατευτικής ικανότητας συζευγμένων βακτηριακών εμβολίων σε παιδιά με το σύνδρομο επίκτητης ανοσολογικής ανεπάρκειας

Abstract

Immunogenicity and immunological memory were evaluated after immunization with PCV-7 and PRP-T in all Greek symptomatic HIV-1 infected children. We also evaluated vaccine-induced immunity to PRP-T in subjects with β-thalassemia and compared it with naturally acquired immunity to Hib. The surrogates used were the kinetics of concentration and avidity of anti-pneumococcal antibodies for serotypes 6B, 14, 19F and 23F, and anti-Hib PRP antibodies, before and after immunization. Fourteen Greek symptomatic HIV children on ART were evaluated. At study entry the median (range) age was 128 (20-163) months. For comparison, we obtained data for 21 healthy subjects of similar age. We also studied 35 patients with β-thalassemia aged 12-30 years (median 23 years) and 10 age-matched healthy individuals. All HIV-1 infected children received two doses of PCV-7 1 month apart and a booster dose 12 months later. In the study of immunological memory induced by PRP-T, all seropositive children were offered two anamnestic doses of the vaccine 18 months apart. In the study of immunity to Hib in patients with β-thalassemia, all study subjects received one dose of PRP-T. Our findings suggest that immunogenicity and immunological memory induced by PCV-7 and PRP-T are impaired among symptomatic HIV infected children on ART and cannot be restored by repeated immunizations. In contast, immunogenicity of PRP-T in β-thalassemic patients was not impaired. Using as surrogates immunogenicity and immunological memory, we expect that effectiveness of conjugated polysaccharide vaccines is going to be reduced among symptomatic HIV-1 infected children