Investigators: Deborah Lehmann, Lea-ann Kirkham, Peter Jacoby, Peter Richmond, Ruth Thornton, Willie Pomat
Summary: We are comparing immune responses to different schedules of the 3 available pneumococcal vaccines in Papua New Guinean infants to provide information to policy makes on the best vaccines and vaccine schedule to use in PNG. This information will also be relevant for other regions that have high incidence of childhood death from pneumonia. Data from this study will also provide information on how to develop improved vaccines to provide even better protection.
Project description:
This project is in collaboration with the Vaccine Trials Group, The Kids Research Institute Australia and the Papua New Guinea Institute for Medical Research.
Pneumococcal disease is a major killer of young children in low-income countries. The Global Alliance for Vaccines and Immunizations (GAVI) has endorsed US$1.3 billion to fund PCV implementation into low-income countries with high burdens of pneumococcal disease, including Papua New Guinea, but policy on choice of vaccine is hampered by lack of data comparing these vaccines in high-risk infants. Our NHMRC-funded vaccine trial (NHMRC 1087200 CID; NCT01619462) provides a direct comparison of PCV10 and PCV13 in a low-income setting with an accelerated infant schedule, as is being implemented by GAVI. While the extra 3 serotypes in PCV13 improves coverage, the potential protection against NTHi infection by PCV10 needs to be considered, particularly in countries such as PNG with high rates of NTHi pneumonia. We are also investigating whether a PPV23 booster after PCV priming may enhance protection. While PPV23 has been suggested to blunt antibody titre in the short-term, PPV23 also prevents pneumonia and death in PNG children. Recruitment is complete and microbiological and immunological analyses of the specimens is well underway. This includes measuring vaccine impact on NTHi and S. pneumoniae colonisation density by qPCR and functional antibody responses e.g. using the W.H.O. standardised multiplex opsonophagocytosis assay (MOPA). We are also measuring antibodies to putative vaccine antigens using our bioplex platform and antigens from collaborating vaccine manufacturers. This study will directly inform global pneumococcal immunisation policy, which will impact on the 1.2 million annual childhood pneumonia deaths.