A Study To Investigate Alternative Regimens For Pneumococcal Vaccination Of Infants In A Developing Country
Funder
National Health and Medical Research Council
Funding Amount
$1,622,210.00
Summary
Streptococcus pneumoniae (Pnc) is the leading vaccine preventable cause of serious infection in infants. The current Pnc conjugate vaccine is very expensive (approximately USD $200-infant) so it is unlikely to be affordable for most developing countries. Moreover, as health care access in developing countries may be episodic and unreliable, many children do not receive either complete or timely vaccine courses. Therefore, it is important to investigate affordable and flexible ways to deliver thi ....Streptococcus pneumoniae (Pnc) is the leading vaccine preventable cause of serious infection in infants. The current Pnc conjugate vaccine is very expensive (approximately USD $200-infant) so it is unlikely to be affordable for most developing countries. Moreover, as health care access in developing countries may be episodic and unreliable, many children do not receive either complete or timely vaccine courses. Therefore, it is important to investigate affordable and flexible ways to deliver this vaccine, which are safe and effective. A recent WHO-GAVI meeting to address impediments to the introduction of these vaccines in developing countries recognized the need to evaluate other regimens of Pnc conjugate vaccine as an important research priority. This study has been deliberately formulated with that need in mind. The site for this research is Fiji. Although health services are good, Pnc disease, particularly pneumonia, remains the commonest cause of childhood morbidity and mortality. Fiji has good vaccine coverage and was the first Pacific country to introduce Hib vaccine. The arrival of the new, expensive Pnc conjugate vaccine presents a dilemma for Fiji and many similar countries. The expense of this vaccine would consume a large portion of the health budget. This study has two components: 1. A Phase 2 immunogenicity study (involving 750 infants) to evaluate regimens using reduced numbers of doses of Pnc conjugate vaccine, and using timing of dosing and combinations with the Pnc polysaccharide (PS) vaccine that may be more suited to the epidemiology of Pnc disease in developing countries. 2. An epidemiological study will measure the burden of invasive Pnc disease and pneumonia in Fiji. This will be part of a global effort to address these issues, and will be used to develop rapid assessment tools for these diseases in developing countries. We will seek cofounding for this component.Read moreRead less
Antigen Selection In The MHC-restricted Cellular Immune Response
Funder
National Health and Medical Research Council
Funding Amount
$175,570.00
Summary
The body's white cells eliminate microorganisms through the actions of immune lymphocytes and other cells which conspire to kill and neutralise these unwanted guests. When microorganisms hide inside the cells of the body they are still detected by a set of T lymphocytes which have specific receptors for scrutinising the surface of cells for any changes which might signal an intracellular infection. The immune system is ever vigilant in its search for signs of infection which are generally appare ....The body's white cells eliminate microorganisms through the actions of immune lymphocytes and other cells which conspire to kill and neutralise these unwanted guests. When microorganisms hide inside the cells of the body they are still detected by a set of T lymphocytes which have specific receptors for scrutinising the surface of cells for any changes which might signal an intracellular infection. The immune system is ever vigilant in its search for signs of infection which are generally apparent when molecules called antigens are released by microorganisms and captured by the body's cells. This activates lymphocytes resulting in an immune response capable of eliminating the microorganisms. Scrutiny of the body's cells by lymphocytes occurs continuously even when there is no infection present in the body. Following infection of a cell, microbial antigens reveal the infection by their appearance on the cell surface where they are detected by the immune system's lymphocytes. This occurs through a mechanism called antigen presentation. During antigen presentation the proteins inside the cell, including those of any invading microorganism, are first degraded into shorter molecules called peptides. This event is called antigen processing. A fraction of the peptides created by antigen processing are captured by specialised receptors present on all cells. These receptors are called HLA or histocompatibility molecules. This project examines the molecular events which mediate the capture of peptide antigens by HLA molecules. The main focus is on those peptide antigens which elicit killer T cell responses by the immune system. A knowledge of how these peptides are selected for presentation and how they are captured and carried to the cell surface is fundamental to understanding immune responses to microorganisms, tumours, allergens, transplants and self tissues as in autoimmunity. Therefore the study is of great general relevance.Read moreRead less
Immunising Aboriginal Mothers With Pneumococcal Polysaccharide Vaccine To Prevent Infant Ear Disease And Carriage
Funder
National Health and Medical Research Council
Funding Amount
$1,131,530.00
Summary
Aboriginal children experience the highest rates of acute and chronic ear infections in the world, with resultant permanent ear damage, hearing loss and educational disadvantage. These infections are mainly bacterial, and Streptococcus pneumoniae (pneumococcus) is the predominant pathogen. Pneumococcal colonisation and infection begins within days of birth, many months before any potential immunological protection from infant pneumococcal conjugate vaccine may be expected. New strategies are nee ....Aboriginal children experience the highest rates of acute and chronic ear infections in the world, with resultant permanent ear damage, hearing loss and educational disadvantage. These infections are mainly bacterial, and Streptococcus pneumoniae (pneumococcus) is the predominant pathogen. Pneumococcal colonisation and infection begins within days of birth, many months before any potential immunological protection from infant pneumococcal conjugate vaccine may be expected. New strategies are needed to eliminate, or at least delay, this early-onset pneumococcal colonisation. One such strategy is the administration to the mother of pneumococcal vaccine, which may protect the newborn infant by leading to higher titres of transplacental or breast milk pneumococcal antibodies and-or by reducing carriage (and transmission to the infant) of maternal pneumococci. Previous small studies using this strategy have been encouraging, but there have been no studies properly evaluating carriage or disease endpoints in infants. The polysaccharide pneumococcal vaccine is currently recommended for all Aboriginal and Torres Islander persons aged 15 years or more in the Northern Territory but uptake of the vaccine has been poor. We propose to conduct a pilot study to determine if maternal immunisation with this vaccine, either in the third trimester of pregancy of immediately following delivery, can reduce pneumococcal carriage and the prevalence of middle ear disease among Aboriginal infants at seven months of age. We aim to recruit 210 Aboriginal women who have uncomplicated pregnancies from Darwin and remote communities in the Top End of the Northern Territory. Each subject and their infant offspring will be followed-up after vaccination and at birth, one , two and seven months after birth.Read moreRead less