Immunogenicity and safety of a quadrivalent meningococcal tetanus toxoid-conjugate vaccine (MenACYW-TT) vs. a licensed quadrivalent meningococcal tetanus toxoid-conjugate vaccine in meningococcal vaccine-naïve and meningococcal C conjugate vaccine-primed toddlers: a phase III randomised study.

Vaccination remains the best strategy to reduce invasive meningococcal disease. This study evaluated an investigational tetanus toxoid-conjugate quadrivalent meningococcal vaccine (MenACYW-TT) vs. a licensed tetanus toxoid-conjugate quadrivalent meningococcal vaccine (MCV4-TT) (NCT02955797). Healthy toddlers aged 12-23 months were included if they were either meningococcal vaccine-naïve or MenC conjugate (MCC) vaccine-primed (≥1 dose of MCC prior to 12 months of age). Vaccine-naïve participants were randomised 1:1 to either MenACYW-TT (n = 306) or MCV4-TT (n = 306). MCC-primed participants were randomised 2:1 to MenACYW-TT (n = 203) or MCV4-TT (n = 103). Antibody titres against each of the four meningococcal serogroups were measured by serum bactericidal antibody assay using the human complement. The co-primary objectives of this study were to demonstrate the non-inferiority of MenACYW-TT to MCV4-TT in terms of seroprotection (titres ≥1:8) at Day 30 in both vaccine-naïve and all participants (vaccine-naïve and MCC-primed groups pooled). The immune response for all four serogroups to MenACYW-TT was non-inferior to MCV4-TT in vaccine-naïve participants (seroprotection: range 83.6-99.3% and 81.4-91.6%, respectively) and all participants (seroprotection: range 83.6-99.3% and 81.4-98.0%, respectively). The safety profiles of both vaccines were comparable. MenACYW-TT was well-tolerated and demonstrated non-inferior immunogenicity when administered to MCC vaccine-primed and vaccine-naïve toddlers.

Elucidating the degradation mechanism of the cathode catalyst of PEFCs by a combination of electrochemical methods and X-ray fluorescence spectroscopy.

In this study, we report a methodology which enables the determination of the degradation mechanisms responsible for catalyst deterioration under different accelerated stress protocols (ASPs) by combining measurements of the electrochemical surface area (ECSA) and Pt content (by X-ray fluorescence). The validation of this method was assessed on high surface area unsupported Pt nanoparticles (Pt-NPs), Pt nanoparticles supported on TaC (Pt/TaC) and Pt nanoparticles supported on Vulcan carbon (Pt/Vulcan). In the load cycle protocol, the degradation of Pt-NPs and Pt/Vulcan follows associative processes (e.g. agglomeration) in the first 2000 cycles, however, in successive cycles the degradation goes through dissociative processes such as Pt dissolution, as is evident from a similar decay of ECSA and Pt content. In contrast, the degradation mechanism for Pt nanoparticles dispersed on TaC occurs continuously through the dissociative processes (e.g. Pt dissolution or particle detachment), with similar decay rates of both Pt content and ECSA. In the start-up/shut-down protocol, high surface area Pt-NPs follow associative processes (e.g. Ostwald ripening) in the first 4000 cycles, after which the degradation continues through dissociative processes. On the other hand, dissociative mechanisms always govern the degradation of Pt/TaC under start-up/shut-down protocol conditions. Finally, we report that Pt nanoparticles supported on TaC exhibit the highest catalytic activity and long term durability of the three nanoparticle systems tested. This makes Pt/TaC a potentially valuable catalyst system for application in polymer electrolyte fuel cell cathodes.

[Long-term seroprotection against Japanese encephalitis using an inactivated vaccine (Jevax)]. / Séroprotection à long terme avec le vaccin inactivé contre l'encéphalite japonaise (Jevax).

Japanese encephalitis vaccine (Jevax) is an inactivated vaccine using the Nakayama viral strain. Until 2007, Jevax was the only Japanese encephalitis vaccine available in France but the duration of seroprotection after vaccination and exact timing of booster injections was unclear for travelers from non-endemic areas. The purpose of this report is to describe the results of a retrospective study in which neutralizing antibody levels were measured in 71 subjects previously vaccinated with Jevax. All subjects underwent testing at the Pasteur Institute Medical Center as part of preparation for humanitarian missions to endemic Japanese encephalitis areas in 2005-2006. A neutralizing antibody level greater than or equal to 20 was considered as protective. Findings showed that 49 of the 71 subjects (69%) still had protective antibody levels at a median of 4 years after the last Jevax immunization. In multivariate analysis, the only factor correlated with long-term seroprotection was the total number of vaccinations received. Based on these findings, it was concluded that long-term seroprotection after Jevax vaccination requires repeated booster injections even in subjects frequently exposed to the virus. No correlation was found between seroprotection and the interval between the booster injections.

[Vaccinations for the traveling adult solid organ transplant recipient (excluding hematopoietic stem cell transplant recipients)]. / Vaccinations du voyageur adulte transplanté d'organes (à l'exclusion des receveurs de cellules souches hématopoïétiques).

Progress in transplantation technique has offered a growing number of solid organ transplant recipients the opportunity to travel to tropical and low-income countries. The issue of vaccine-preventable diseases is a challenging question in immunocompromised patients including those with solid organ transplant. Since the response to vaccines is weakened in case of chronic organ failure, candidates should be vaccinated early in the course of the disease. Clinicians should implement a vaccinal strategy until the patient is scheduled for transplantation and monitor its efficacy by serological assays. Live attenuated vaccines (such as yellow fever, measles-mumps-rubella, or chicken pox) are contra-indicated in solid organ transplant recipients and, when indicated, should be administered prior to transplantation, particularly in foreign-born patients highly likely to visit friends and relatives in endemic areas. Vaccinations for transplant recipients considering international travel should be realized according to the risk of acquiring vaccine-preventable diseases but also on both tolerance and immune response which are affected by degree and duration of immunosuppression, comorbidities, and type of organ transplanted. Routine and specific vaccinations for solid organ transplant recipients, as well as travel-related vaccination (such as hepatitis A, typhoid, meningococcal meningitis, rabies, tick-born encephalitis, Japanese encephalitis, and cholera) should be considered during a specific pretravel medical consultation. However, vaccination should be avoided in the 6 months following transplantation when patients are usually receiving the highest doses of immunosuppressive drugs. In this comprehensive review, we provide vaccination schedules based on published studies and guidelines for vaccination of solid organ transplant recipients.

The role of non-covalent interactions in electrocatalytic fuel-cell reactions on platinum.

The classic models of metal electrode-electrolyte interfaces generally focus on either covalent interactions between adsorbates and solid surfaces or on long-range electrolyte-metal electrostatic interactions. Here we demonstrate that these traditional models are insufficient. To understand electrocatalytic trends in the oxygen reduction reaction (ORR), the hydrogen oxidation reaction (HOR) and the oxidation of methanol on platinum surfaces in alkaline electrolytes, non-covalent interactions must be considered. We find that non-covalent interactions between hydrated alkali metal cations M(+)(H(2)O)(x) and adsorbed OH (OH(ad)) species increase in the same order as the hydration energies of the corresponding cations (Li(+) >> Na(+) > K(+) > Cs(+)) and also correspond to an increase in the concentration of OH(ad)-M(+)(H(2)O)(x) clusters at the interface. These trends are inversely proportional to the activities of the ORR, the HOR and the oxidation of methanol on platinum (Cs(+) > K(+) > Na(+) >> Li(+)), which suggests that the clusters block the platinum active sites for electrocatalytic reactions.

Epidemiology and prophylaxis of rabies in humans in France: evaluation and perspectives of a twenty-five year surveillance programme.

The National Reference Centre for Rabies (NRC) was created at the Pasteur Institute after the fox epizootic reached the French territory. The missions of the NRC include, among others, the surveillance of rabies cases in humans and rabies post-exposure prophylaxis (PEP) treatments. The surveillance has been effective since 1982. A Bulletin on the Epidemiology and the Prophylaxis of Rabies in Humans in France is published every year. This Bulletin is now available on the Internet for Human Health and Veterinary national and local Authorities. Since 2005, data is collected with new software, Voozanoo, directly via the Internet. Twenty cases of rabies in humans have been reported since 1970. There were no indigenously acquired cases. The number of PEP treatments peaked in 1990, when the number of cases in the wild fauna was at its acme. Following the decrease of rabies cases in the wild fauna, PEP decreased by 60%. Nevertheless, about4,000 PEP treatments are still carried out. These patients have been exposed to bats or to rabid animals illegally introduced onto the French territory, or during a stay in rabies enzootic countries, or to unobservable animals. The study of this database leads to a number of conclusions: canine variants acquired directly in canine enzootic areas, that are translocated, or acquired through iatrogenic exposure, are responsible for the majority of cases; bats appear to be an increasing source of exposure; PEP surveillance is of utmost importance to monitor and to improve the quality of case management.

[Antiviral immunization of immunocompromised adults, literature review]. / Vaccination antivirale des adultes immunodéprimés, revue de la littérature.

PURPOSE: Immunization, by preventing infections, has a major interest for the immunocompromised subjects. The aim of this article is to make a point on data concerning efficacy (in terms of immunogenicity) and safety of viral vaccines available in France and to synthesize existing guidelines for four groups of patients: solid organ and hematopoietic stem cell transplant recipients, HIV infected persons and patients treated by immunosuppressive drugs for a systemic disease. CURRENT KNOWLEDGE AND KEY POINTS: Available data about vaccines immunogenicity and safety for immunocompromised adults are rare. However, those data indicate that, when immunization contraindications and recommendations are applied, vaccines remain well tolerated and most of the time immunogenic, even if the percentage of responders is lower compared to non immunocompromised persons. Still, the specific guidelines that have been elaborated for immunization of immunocompromised adults are imprecise and incomplete, emphasizing a lack of data about this topic. FUTURE PROSPECTS: Clinical studies remain necessary to precise vaccines immunogenicity and safety for immunocompromised adults. In the meantime, a harmonization of immunization practices for immunocompromised adults should be proposed, so as to help practitioners to succeed a better immunization coverage for these patients.

The role of anions in surface electrochemistry.

Some issues of the current state of understanding in the surface electrochemistry are discussed, with emphases on the role of specifically adsorbing anions in hydrogen adsorption and oxide formation, adsorption and ordering of molecular adsorbates and metal ions, metal deposition, restructuring and stability of surface atoms, and kinetics of electrochemical reactions.