Safety and immunogenicity of a seasonal trivalent inactivated split influenza vaccine: a phase I randomized clinical trial in healthy Serbian adults

This study was a phase I double-blind, randomized, placebo-controlled trial to evaluate the safety and immunogenicity of a Serbian-produced seasonal trivalent split, inactivated influenza vaccine in healthy adults. The vaccine was manufactured in eggs by the Torlak Institute of Virology, Vaccines and Sera, Belgrade, Serbia and contained A/H1N1, A/H3N2 and B viruses. The clinical trial took place at the Clinical Center of Serbia in Belgrade. Sixty healthy volunteers, aged 18-45years, were enrolled in the trial. On the day of immunization, volunteers were randomly assigned to receive either a single dose of the trivalent seasonal influenza vaccine (15g of hemagglutinin per strain) or placebo (phosphate-buffered saline). Subjects were monitored for adverse events through a clinical history and physical examination, and blood was taken for testing at screening and on day 8 to assess vaccine safety. Serum samples obtained before and 21days after immunization were tested for influenza antibody titers using hemagglutination-inhibition (HAI) and microneutralization (MN) tests. No serious adverse events were reported. Pain and tenderness at the injection site were the most commonly reported symptoms in both vaccine and placebo groups. Overall, serum HAI responses of fourfold or greater magnitude were observed to H1, H3, and B antigen in 80%, 75%, and 70% of subjects, respectively. Seroprotection rates as measured by HAI were also high (100%, 100% and 86.67%, respectively, for H1, H3 and B). Thus, Torlak's seasonal trivalent influenza vaccine was not associated with adverse events, was well-tolerated and immunogenic. It should be further evaluated in clinical trials to provide sufficient safety and immunogenicity data for licensing in Serbia

Molecular characterization of vancomycin-resistant enterococci in Serbia: Intensive care unit as the source

The purpose of this study was to evaluate the molecular relatedness of clinical isolates of vancomycin-resistant enterococci (VRE) collected from patients of the Clinic for Infectious and Tropical Diseases in Belgrade. Among 40 isolates available for the investigation, 36 were identified as Enterococcus faecium, whereas 2 were Enterococcus faecalis and Enterococcus raffinosus, respectively. Pulsed-field gel electrophoresis (PFGE) typing revealed 21 strain types, comprising 7 clusters which contained at least two isolates and 14 unique PFGE patterns. Although we searched for pathogenicity factor genes (gelE, cylB, asa1, efaAfs, esp, cpd, cob) in representatives of all macro-restriction patterns, they have been confirmed in only one clone of E. faecalis. Genes esp and hyl, commonly found in E. faecium, were yilded in 10 macro-restriction patterns of this species, and their presence could not be ascribed to clonally related strains (p = 0.05). All VRE isolates were multiresistant and positive for vanA gene. Twenty strains of VRE and 6 clusters obtained from Intensive care unit (ICU) are proof of intensive transmission of these microorganisms at this department. The results of this study suggest wide genotypic variability among the clinical VRE isolates, but also intrahospital dissemination of some of them

Predictors of Hospitalization and Admission to Intensive Care Units of Influenza Patients in Serbia through Four Influenza Seasons from 2010/2011 to 2013/2014

A retrospective analysis of the surveillance data on laboratory confirmed cases of influenza in 4 post pandemic seasons in Serbia was performed to evaluate predictors of hospitalization and admission to intensive care units (ICU). The specimens, including nasal and throat swabs were tested for influenza. Univariate and multivariate logistic regression analyses were perfoimed. Data of a total of 777 confirmed influenza cases were analyzed. Age gt 65 years, the presence of any co-morbidity or the presence of gt = 2 comorbidities, infection with influenza virus subtype A (H1) pdm09, and an interval greater than 3 days between symptom onset and the first physician visit, were independently associated with hospital admission. These variables, as well as infection with non-subtype influenza virus A, were predictors for ICU admission. Obesity and chronic neurological disease were independent predictors for ICU admission but not hospitalization. Overall, 41.7% of patients with influenza had at least one co-morbidity, but only 3% of all patients were vaccinated against influenza. Identification of high risk groups and education of these groups regarding their increased susceptibility to severe forms of influenza, and in particular regarding the importance of influenza vaccination, is essential