Safety and immunogenicity of booster immunization with 7-valent pneumococcal conjugate vaccine in children with idiopathic nephrotic syndrome.

Safety and immunogenicity of a booster dose of 7-valent pneumococcal conjugate vaccine (PCV7) were evaluated in 29 patients with idiopathic nephrotic syndrome (INS), who had been primed 12 months earlier with one dose of PCV7. PCV7 was not associated with increased risk of INS relapse (RR=0.77, p=0.8) and serotype-specific antibodies increased in all subjects at 1 month (p<0.01). The quantitative characteristics of immune response and the effect of treatment with mycophenolate mofetil and/or cyclosporine A following booster PCV7 were similar with primary response. Additional PCV7 doses could be safely given in children with INS to increase circulating antibodies above the protective threshold.

Safety, immunogenicity and kinetics of immune response to 7-valent pneumococcal conjugate vaccine in children with idiopathic nephrotic syndrome.

Safety, immunogenicity and kinetics of 7-valent pneumococcal-conjugate vaccine (PCV7) immune response were evaluated in 33 children with idiopathic nephrotic syndrome (INS) and 16 controls. PCV7 was not associated with increased risk of relapse (RR=0.80, p=0.61). Serotype (PS)-specific antibodies increased in all subjects at 1 month (p<0.01) with inferior immunogenicity for 3/7 PS in patients on immunomodulators (p<0.02). Most patients retained protective antibodies at 12-14 months although at lower levels for 4/7 PS (p<0.08). Different PS kinetics in INS suggests antibody monitoring and revaccination when necessary for protection from pneumococcal infections.

The effect of 23-valent pneumococcal polysaccharide vaccine on immunological priming induced by 7-valent conjugate vaccine in asplenic subjects with beta-thalassemia.

The effect of the 23-valent pneumococcal polysaccharide vaccine (PPV) on the 7-valent conjugate (PCV) vaccine-induced priming was evaluated in 35 splenectomised beta-thalassemics [median (range) age: 30 (12-41) years] vaccinated with either PCV/PPV or two PCVs 1 month apart, followed by a PPV booster 12 months later. 28/35 had already received 1-3 PPVs in the past. Different schedules induced similar anamnestic responses; however priming for 3/5 serotypes induced by one or two PCVs, was inferior in subjects who had received > or =2 PPVs in the past when compared with 23 aged-matched PPV-naïve beta-thalassemics. One PPV following PCV does not affect PCV priming; multiple PPVs induce hyporesponsiveness for some serotypes in splenectomised subjects with beta-thalassemia.

Natural and vaccine-induced immunity against Haemophilus influenzae type b in patients with beta-thalassemia.

Natural and vaccine-induced immunity and immunological memory to Haemophilus influenzae type b (Hib) were evaluated in adolescents and adults with beta-thalassemia. At baseline 10/23 (43%) unvaccinated patients had naturally acquired anticapsular antibodies >0.15 microg/ml, the threshold of protection, compared to 9/10 (90%) aged-matched controls. Hib-conjugate vaccine (PRP-T) induced protective immune responses in all subjects and there were no differences in geometric mean concentrations at 1 month (GMC) between patients and controls (69.04 versus 40.5, respectively). Vaccine-induced immunological memory was assessed in 12 subjects with beta-thalassemia who had been vaccinated against Hib in the past. All subjects had retained PRP>1 microg/ml at baseline; PRP-T revaccination induced anamnestic responses which were similar, in terms of post vaccination antibody concentration (P=0.54) and avidity (P=0.08), with primary responses given by previously unvaccinated patients. A single dose of PRP-T induces adequate and long-lasting immunity and should be given in all unvaccinated adolescents and adults with beta-thalassemia.

Immunogenicity and immunological memory induced by a 7-valent pneumococcal CRM197 conjugate vaccine in symptomatic HIV-1 infected children.

A 7-valent CRM197 conjugate pneumococcal vaccine (PCV)-induced immune response were evaluated in all Greek symptomatic HIV-1 infected children and 21 age-matched controls. PCV immunogenicity was inferior in HIV patients compared with the controls although differences in geometric mean concentrations (GMC) were not significant (P>.05). Immune responses were strikingly different after anamnestic immunization, given in all study subjects, 12 months later. HIV-positive children achieved lower GMC for all serotypes compared with the controls (P=.002) and avidity for all except serotype 6B was inferior compared to baseline. Long-term PCV effectiveness is expected to be reduced among symptomatic HIV-1 infected children.