Clinical Research Directory

The Effects of Antibiotic Exposure in Early Infancy on Vaccine Responses

This prospective cohort study will include 200 term children born in Landspitali University Hospital in Iceland. The cohort will be divided into four groups according to antibiotic exposure of which one is the control group. Children's immune responses to live oral rotavirus vaccine as well as conventional vaccinations given at three, five and 12 months old will be determined by measuring salivary and serologic responses. Responses will be compared between the four groups. Stool samples will also be collected from participants and the composition of the microbiome compared between the four groups.

The Bloom Infant Probiotic (BIP) Study

The goal of this clinical trial is to investigate whether administering a probiotic (Infloran®) to infants who received antibiotics in the first 28 days of life can restore or enhance their immune response to routine vaccines. Antibiotic use in the first weeks of life can lower the levels of beneficial gut bacteria, such as bifidobacteria, which play a key role in immune function. As a result, infants treated with antibiotics may produce fewer antibodies after routine vaccinations, leaving them less protected against infections. The main questions this study aims to answer are: * Does treatment with the probiotic Infloran® improve the geometric mean concentrations (GMCs) of anticapsular antibodies against at least 11 serotypes included in the pneumococcal conjugate vaccine (PCV20) in serum samples collected at 6 months of age compared with placebo in infants treated with antibiotics in the neonatal period? * Does treatment with the probiotic Infloran® improve the GMCs for the pneumococcal conjugate vaccine (PCV20) at 12 months of age compared with placebo in infants treated with antibiotics in the neonatal period? * Does treatment with the probiotic Infloran® improve the GMCs of other routine childhood vaccines at 6 and 12 months of age compared with placebo in infants treated with antibiotics in the neonatal period? * Does treatment with the probiotic Infloran® increase the proportion of infants achieving seroprotective antibody levels for pneumococcal antigens compared to placebo in infants treated with antibiotics in the neonatal period? * What are the differences in antigen specific T cell responses, flow cytometry, blood transcriptomics, and gut microbiota composition in the probiotic (Infloran®) vs placebo groups in infants treated with antibiotics in the neonatal period? Researchers will compare infants who receive Infloran® (a probiotic containing Bifidobacterium bifidum and Lactobacillus acidphilus) with those who receive a placebo (which contains the same excipients as Infloran® but does not contain any bacterial strains). Participants will: * Be randomly assigned to receive either a 14-day course of probiotic Infloran® or a placebo. * Provide blood samples (3-5 mL) at 6 weeks, 6.5 weeks (optional blood-draw for exploratory endpoint), 6 months and 12 months of age. * Provide stool samples at four timepoints: prior to starting the intervention (probiotic/placebo), on day 7, on day 14 after completion of the study supplement, and prior to their first vaccination at 6 weeks of age. * Receive routine vaccinations at 6 weeks, 4 months and 6 months in line with the National Immunisation Program * Complete surveys to collect information regarding probiotic/placebo administration and vaccination related side effects This study aims to recruit 360 infants to assess whether this probiotic treatment following antibiotic exposure improves the immunogenicity of vaccinations. The information from this study will improve our understanding of how probiotic intervention can support optimal immune responses to vaccination in early life. The findings could potentially influence public health strategies, offering a new way to support optimal vaccine responses in antibiotic-treated infants.

Restoration of Antibiotics Related Infant Microbiota Perturbations by Autologous Fecal Transplant

Antibiotics are lifesaving therapeutic drugs which have been used by adults, children, and infants alike for decades. There is an increase in global use of antibiotics over the course of lifetime and earlier in lifetime, with some countries recording as high as 12 courses a year in children younger than two. While antibiotics are successful in eradicating many pathogenic bacteria, research has demonstrated significant effect on beneficial gut microbiota, including long-lasting shift in the dynamics, composition, richness, and maturity of the intestinal flora. Microbiota alterations during early life, including through antibiotics use as well as birth via C-section, constitute a developmental perturbation, which increases the risk of modern diseases of immune and metabolic dysfunction. Strong epidemiological evidence suggests associations between early stressors of the microbiota and a number of common diseases, such as obesity, asthma, allergies, celiac disease, and Type 1 Diabetes. Furthermore, excess antibiotic exposure is associated with the development of neurological and psychiatric disorders. Currently, no strategies exist to restore the microbiome other than reliance on spontaneous repair mechanism, which often takes months in a healthy individual barring further antibiotic exposure. Contrary to popular belief, ingestion of probiotics, particularly after antibiotics, has been demonstrated to slow down the repair as it introduces an exogenous and massive amounts of only a few types of bacterial strains into a finely-tuned ecosystem of hundreds of different strains. It is hypothesized that by preserving the child's microbiome prior to antibiotic therapy and reintroducing it afterwards through an autologous fecal matter transplant (FMT) will assist in a quick, effective, and host-specific microbiome recolonization to the levels and patterns to those prior to antibiotics. This would in turn reduce the overall loss of microbiome diversity over the child's lifespan, essentially providing a 'reset' option to the child's most unadulterated version of microbiome. This approach utilizes delivering the sample by mixing it in maternal milk or formula and feeding it to the child through a bottle, which can be performed anywhere without any discomfort for the child.

Invasive Pneumococcal Disease Study

After 7 then 13 valent pneumococcal conjugate vaccine implementation in France in children, we will evaluate the impact of this vaccination on invasive pneumococcal disease (IPD). We will describe the clinical characteristics of IPD, pneumococcus serotyping, underlying conditions and vaccination status.

National Bacterial Meningitis Study

Bacterial meningitis is a major cause of morbidity and mortality in childhood. Antibiotic treatment recommendations are based on epidemiological and susceptibility data. The epidemiology of bacterialméningitis has changed in recent years, mainly owing to widespread use of different conjugate vaccines. The aim of this prospective national survey is to describe epidemiology of bacteria implicated in bacterial meningitis in children.