Long-term Seroprotection of Varicella-zoster Immunization in Pediatric Liver Transplant Recipients.

Background: Chickenpox is a highly contagious vaccine-preventable disease that can lead to severe complications, especially in immunocompromised patients. Varicella-zoster virus (VZV) vaccine appears to be safe and immunogenic in pediatric solid organ transplant recipients, but there are few data on the long-term vaccine-induced seroprotection.

Methods: In this prospective interventional study, we offered 2 doses of VZV vaccine to all eligible and nonseroprotected children seen 1 year after liver transplant.

Boosting Teenagers With Acellular Pertussis Vaccines Containing Recombinant or Chemically Inactivated Pertussis Toxin: A Randomized Clinical Trial.

Background: Protection induced by acellular pertussis (aP) vaccines is partial and short-lived, especially in teenagers, calling for novel immunization strategies.

Methods: We conducted an investigator-driven proof-of-concept randomized controlled trial in aP-primed adolescents in Geneva to assess the immunogenicity and reactogenicity of a novel recombinant aP (r-aP) vaccine including recombinant pertussis toxin (PT) and filamentous hemagglutinin (FHA) coadministered with tetanus-diphtheria toxoids (Td), compared to a licensed tetanus-diphtheria-aP vaccine containing chemically detoxified PT (cd/Tdap). The primary immunological endpoints were day 28/365 geometric mean concentrations (GMCs) of total and neutralizing anti-PT antibodies.

Toll-Interleukin 1 Receptor Domain-Containing Adaptor Protein 180L Single-Nucleotide Polymorphism Is Associated With Susceptibility to Recurrent Pneumococcal Lower Respiratory Tract Infections in Children.

Lower respiratory tract infections (LRTI) are often caused by () and can be recurrent in 8% of children older than 2 years of age. is recognized by pattern-recognition receptors (PRRs) of the innate immune system, in particular toll-like receptors (TLRs) 2 and 4. To assess whether a defect somewhere along this TLR signaling pathway increases susceptibility to recurrent pneumococcal LRTI, we conducted a prospective case-control study with 88 healthy individuals and 45 children with recurrent LRTI aged 2-5 years old.

Determinants of antibody persistence across doses and continents after single-dose rVSV-ZEBOV vaccination for Ebola virus disease: an observational cohort study.

Background: The recombinant vesicular stomatitis virus (rVSV) vaccine expressing the Zaire Ebola virus (ZEBOV) glycoprotein is efficacious in the weeks following single-dose injection, but duration of immunity is unknown. We aimed to assess antibody persistence at 1 and 2 years in volunteers who received single-dose rVSV-ZEBOV in three previous trials.

Methods: In this observational cohort study, we prospectively followed-up participants from the African and European phase 1 rVSV-ZEBOV trials, who were vaccinated once in 2014-15 with 300 000 (low dose) or 10-50 million (high dose) plaque-forming units (pfu) of rVSV-ZEBOV vaccine to assess ZEBOV glycoprotein (IgG) antibody persistence.

A dose-dependent plasma signature of the safety and immunogenicity of the rVSV-Ebola vaccine in Europe and Africa.

The 2014-2015 Ebola epidemic affected several African countries, claiming more than 11,000 lives and leaving thousands with ongoing sequelae. Safe and effective vaccines could prevent or limit future outbreaks. The recombinant vesicular stomatitis virus-vectored Zaire Ebola (rVSV-ZEBOV) vaccine has shown marked immunogenicity and efficacy in humans but is reactogenic at higher doses.

Memory B cell compartment constitution and susceptibility to recurrent lower respiratory tract infections in young children.

A proportion of children have recurrent LRTIs, mostly as a result of Spn, which persist after 2 years of age. Here, we investigate, by flow cytofluorometry, the constitution of the memory B cell compartment in 90 healthy children and 49 children with recurrent LRTIs to determine if an increased susceptibility to recurrent LRTIs results from a delayed or abnormal ontogeny with poor antibody-mediated protection. Total IgA, IgM, IgG, and IgG subclasses were measured by nephelometry, as well as antipneumococcal antibodies by ELISA.

Varicella-zoster immunization in pediatric liver transplant recipients: safe and immunogenic.

Varicella can have a severe course in immunosuppressed patients. Although prevention is fundamental, live-attenuated varicella-zoster (VZV) vaccine is not currently recommended in transplant recipients. Our aims were to (1) evaluate VZV immunity in pediatric liver transplant (LT) recipients; (2) immunize (two doses) seronegative patients post-LT; (3) monitor vaccine safety, (4) assess B and T cell vaccine responses.

Influence of age, social patterns and nasopharyngeal carriage on antibodies to three conserved pneumococcal surface proteins (PhtD, PcpA and PrtA) in healthy young children.

The acquisition of specific antibodies is paramount to protect children against pneumococcal diseases, and a better understanding of how age, ethnicity and/or Streptococcus pneumoniae (Spn) nasopharyngeal carriage influence the acquisition of antibodies to pneumococcal surface proteins (PSP) is important for the development of novel serodiagnostic and immunisation strategies. IgG antibody titres against three conserved PSP (PhtD, PcpA and PrtA) in the sera of 451 healthy children aged 1 to 24 months from Israel [Jewish (50.1 %) and Bedouin (49.

Responses of solid organ transplant recipients to the AS03-adjuvanted pandemic influenza vaccine.

Background: Solid organ transplant (SOT) recipients are a priority group for influenza vaccination and strategies enhancing immunogenicity are needed.

Methods: We determined adverse reactions, changes in biomarkers of graft function and immune responses to two doses of the AS03-adjuvanted influenza A/09/H1N1 vaccine in 216 SOT recipients and in 138 controls after one dose. Antibody responses were measured by haemagglutination inhibition and confirmed by microneutralization.

A prospective study of the factors shaping antibody responses to the AS03-adjuvanted influenza A/H1N1 vaccine in cancer outpatients.

Purpose: To identify the determinants of antibody responses to adjuvanted influenza A/H1N1/09 vaccines in a cohort of cancer outpatients.

Patients And Methods: Patients with cancer and controls were enrolled in a prospective single-center field study. Two doses of AS03-adjuvanted pandemic influenza vaccine were administered to patients and one dose was administered to controls.

Failure to elicit seroresponses to pneumococcal surface proteins (pneumococcal histidine triad D, pneumococcal choline-binding protein A, and serine proteinase precursor A) in children with pneumococcal bacteraemia.

Pneumococcal surface proteins (PSPs) elicit antibody responses in infants and young children exposed to Streptococcus pneumoniae. These seroresponses could contribute to the aetiological diagnosis of pneumococcal disease, e.g.

Antibody responses to natural influenza A/H1N1/09 disease or following immunization with adjuvanted vaccines, in immunocompetent and immunocompromised children.

Objectives: To compare antibody responses elicited by influenza A/H1N1/09 disease and immunization with adjuvanted vaccines, in immunocompetent or immunocompromised children.

Study Design: Prospective parallel cohort field study enrolling children with confirmed influenza A/H1N1/09 disease or immunized with 1 (immunocompetent) or 2 (immunocompromised) doses of influenza A/H1N1/09 squalene-based AS03- or MF59-adjuvanted vaccines. Antibody geometric mean titers (GMT) were measured by hemagglutination inhibition (HAI) and microneutralization (MN) assays 4-6 weeks after vaccination/disease.

Impact of synthetic and biologic disease-modifying antirheumatic drugs on antibody responses to the AS03-adjuvanted pandemic influenza vaccine: a prospective, open-label, parallel-cohort, single-center study.

Objective: To identify the determinants of antibody responses to adjuvanted split influenza A (H1N1) vaccines in patients with inflammatory rheumatic diseases.

Methods: One hundred seventy-three patients (82 with rheumatoid arthritis, 45 with spondylarthritis, and 46 with other inflammatory rheumatic diseases) and 138 control subjects were enrolled in this prospective single-center study. Controls received 1 dose of adjuvanted influenza A/09/H1N1 vaccine, and patients received 2 doses of the vaccine.

Immunity to pneumococcal surface proteins in children with community-acquired pneumonia: a distinct pattern of responses to pneumococcal choline-binding protein A.

The aetiological diagnosis of community-acquired pneumonia (CAP) is challenging in children, and serological markers would be useful surrogates for epidemiological studies of pneumococcal CAP. We compared the use of anti-pneumolysin (Ply) antibody alone or with four additional pneumococcal surface proteins (PSPs) (pneumococcal histidine triad D (PhtD), pneumococcal histidine triad E (PhtE), LytB, and pneumococcal choline-binding protein A (PcpA)) as serological probes in children hospitalized with CAP. Recent pneumococcal exposure (positive blood culture for Streptococcus pneumoniae, Ply(+) blood PCR finding, and PSP seroresponse) was predefined as supporting the diagnosis of presumed pneumococcal CAP (P-CAP).

Frequent failure of adolescent booster responses to tetanus toxoid despite infant immunization: waning of infancy-induced immune memory?

To define the capacity of a tetanus toxoid booster to reactivate infant-triggered immunity, anti-tetanus antibodies were assessed before and after boosting 162 adolescents and 219 children from Mfou (Cameroon). Among 63 adolescents with 3 recorded dose of infant DTP, 29/63 (46%) responded with a > or =4-fold increase of antibody titers, 35/63 (55%) reaching the 0.10UI/ml threshold.

Protracted course of lymphocytic choriomeningitis virus WE infection in early life: induction but limited expansion of CD8+ effector T cells and absence of memory CD8+ T cells.

Viral infections in human infants frequently follow a protracted course, with higher viral loads and delayed viral clearance compared to viral infections in older children. To identify the mechanisms responsible for this protracted pattern of infection, we developed an infant infection murine model using the well-characterized lymphocytic choriomeningitis virus (LCMV) WE strain in 2-week-old BALB/c mice. In contrast to adult mice, in which viral clearance occurred as expected 8 days after infection, LCMV titers persisted for several weeks after infection of infant mice.

'Oncocheck': an international external quality assessment scheme for immunoassays of tumor markers.

Starting from November 1990, an international External Quality Assessment Scheme (EQAS) for immmunoassays of tumor markers has been organized. Presently, 238 laboratories from France, Germany, Italy, Japan and Spain participate in the scheme. In this report the main features of the EQAS and data processing are outlined.