Immunological responses following pneumococcal conjugate vaccination

Summary This project will measure cellular immune responses following reduced dose PCV schedules in Vietnam using flow cytometry. Results from this study will facilitate our understanding of PCV-induced immunity and will contribute to the global evidence on reduced dose PCV evaluation.

Project Details

Pneumococcal diseases such as pneumonia, meningitis and sepsis are the biggest killers of children under 5 years of age worldwide, mostly in low- and middle-income countries (LMICs). There are two currently licensed pneumococcal conjugate vaccines (PCVs), PCV10 (Synflorix®, GlaxoSmithKline) and PCV13 (Prevnar-13®, Pfizer). As these are expensive vaccines, there has been an emphasis on PCV schedules with reduced numbers of doses that rely more on herd immunity, mediated by reduction in carriage, rather than individual protection. However, the immunological determinants of long-term protection against pneumococcal carriage are poorly understood. In Vietnam, we are currently undertaking a randomised trial of reduced dose schedules of the two licensed PCVs, and have developed approaches to measure B-cell memory (Bmem), follicular T helper cells (Tfh), Th17 cells and agglutinating antibodies to comprehensively examine the immune response following PCV. This project will measure cellular immune responses following reduced dose PCV schedules in Vietnam using flow cytometry. Results from this study will facilitate our understanding of PCV-induced immunity and will contribute to the global evidence on reduced dose PCV evaluation.