Graduate Research Degree Awarded - Isatou Jagne

Congratulations to Isatou Jagne-  Graduate Research Degree Awarded 26 September 2024

Degree: MPhil
Supervisors: Prof Fiona Russell, A/Prof Claire von Mollendorf, A/Prof Catherine Satzke
Advisory Committee: Prof Marc Seal (Chair), Prof Kim Mulholland

Thesis Title: Measuring pneumococcal conjugate vaccine impact: further defining the role of nasopharyngeal carriage studies

Thesis Summary: 

This thesis examines the impact of pneumococcal conjugate vaccines (PCVs) on nasopharyngeal pneumococcal density, a key factor in pneumococcal disease transmission and severity, among children under five years of age. A systematic review showed inconsistent effects of PCVs on density, likely due to differences in study methods and epidemiology.

Research in Papua New Guinea (PNG) and Lao People’s Democratic Republic (PDR) found no clear associations between host factors and pneumococcal density in unvaccinated children. PCV13 reduced vaccine-type (VT) density among vaccinated children in PNG but had no effect in Lao PDR, potentially due to the impact of indirect vaccine effects. In PNG, two or three doses of PCV13 reduced VT density in children with pneumonia, but a single dose had no effect. However, this reduction was small and unlikely to affect disease transmission.

The thesis emphasises the context-dependent nature of PCVs' effect on density and recommends further research to clarify this relationship and its role in reducing pneumococcal disease.

Date awarded: 26 September 2024