Responses to Rabies Vaccine in Adults With or Without Antibiotics
Condition: Rabies Human
MeSH terms: Rabies
Study type: Interventional
Phase: Phase 4

Summary: 
      The use of antibiotics changes micro-organisms in the intestines which may impact the body's
      vaccine immune response and alter the effectiveness of the rabies vaccine.

      There will be two randomized groups (1:1 randomization). Group A will start taking an
      antibiotic regimen by mouth 3 days prior to vaccination and continue taking antibiotics the
      day of rabies vaccination and one day after vaccination for a total of 5 days. Group B will
      only receive the rabies vaccination and will not take any antibiotics. The dosage of each
      antibiotic is taken from their respective package inserts and does not exceed the maximum
      dose allowed for each antibiotic.

      The purpose of the study is to look at immune response after rabies vaccination with or
      without the use of antibiotics from day of vaccination to 28 days post vaccination in both
      groups.
    

Detailed description: 
      Vaccination has been one of the most important and cost-effective public health interventions
      to provide protection against infectious diseases. Since the introduction of the first
      vaccine in 1796, there have been countless advances in the field. However, numerous gaps
      remain to be addressed. An important gap is understanding the mechanisms that lead to
      suboptimal immune responses to vaccination. It has been shown that the magnitude of the
      immune response produced by vaccines is highly variable among individuals, with both genetic
      and environmental factors playing an important role. More recently, emphasis is being placed
      on the role of the microbiota in vaccine immunogenicity. The microbiome is the collection of
      all microbial cells in and on the human body, with the majority being in the gastrointestinal
      tract. The composition of the microbiome has the ability to affect B and T cell development,
      which are important aspects of the adaptive immune system and major responders to
      vaccination.

      Due to this link between microbiome and the immune system, it is important to further
      understand the impact of the microbiome on the immune response to vaccination. This can be
      done using systems vaccinology, which is the application of systems biology in vaccinology to
      predict vaccine efficacy. The aim is to find molecular signatures, or patterns of gene
      expression induced after vaccination, which can be used to correlate and predict the
      development of protective immunity. The goal of this study is to determine whether alteration
      of microbiota by antibiotic exposure can negatively impact the immunogenicity of rabies
      vaccine, and to assess the innate and adaptive immune mechanisms responsible for that
      phenomenon.

      Half of the study participants will receive the rabies vaccine alone and half will receive
      the rabies vaccine along with a 5 day course of antibiotics. The primary objective of this
      study is to compare antibody titers 28 days after vaccination with the rabies vaccine in
      adults with or without use of antibiotics.
    

Intervention name(s): Rabies Vaccine; Metronidazole; Vancomycin; Neomycin Sulfate
Intervention type(s): Biological; Drug; Drug; Drug
Intervention description(s): A 1.0 milliliter (mL) dose of Imovax® will be given to participants on Day 0 and Day 28 of the study.; The antibiotic regimen will be given for five days beginning 3 days prior to vaccination, on the vaccination day, and one day after vaccination for a total for 5. The regimen will include 500 milligrams (mg) of Flagyl taken by mouth three times a day.; The antibiotic regimen will be given for five days beginning 3 days prior to vaccination, on the vaccination day, and one day after vaccination for a total for 5. The regimen will include 125 mg of Vancocin taken by mouth four times a day.; The antibiotic regimen will be given for five days beginning 3 days prior to vaccination, on the vaccination day, and one day after vaccination for a total for 5. The regimen will include 500 milligrams (mg) of Neomycin sulfate taken by mouth three times a day.
Other intervention name(s): Imovax; Flagyl; Vancocin; Mycifradin
Intervention MeSH terms: Metronidazole; Vancomycin; Neomycin
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Longitudinal and Randomized
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: Rabies Vaccine; Antibiotics; Biopsy