Safety and Immunogenicity of 10-valent and 13-valent Pneumococcal Conjugate Vaccines in Papua New Guinean Children

Overview

The study aims to evaluate the safety and immunogenicity of the 10-valent and 13-valent pneumococcal conjugate vaccines when administered in an accelerated schedule in Papua New Guinean children, who experience early dense upper respiratory tract colonisation with a broad range of pneumococcal serotypes, and to compare antibody titres following a booster dose of polysaccharide vaccine at 9 months with those children who received no booster at the same age.

The primary aim of the study is to determine whether PCV10 and PCV13 are safe and immunogenic in PNG infants for the serotypes in the respective vaccines. This study is important for the following reasons: 1. There is a lack of data worldwide on immunogenicity in populations with very high early onset of dense URT carriage. 2. The EPI immunisation schedule is very accelerated in PNG (ages 1,2 and 3 months). 3. There are not data on functional antibody to PCVs in PNG. 4. There are no data on NTHi Protein D antibody responses in PNG and worldwide in population with very high URT carriage rates from a young age, i.e. those most likely to benefit from a vaccine including NTHi protein carrier. 5. It is important to investigate impact of vaccine on carriage density in view of our finding of limited impact of 7vPCV on URT carriage. 6. There is no data on antibody responses following 10v or 13v PCV to booster with PPV as young as 9 months of age (which would be the most appropriate within the current PNG EPI schedule and in the many other third world countries). 7. There is no data on antibody responses (including functional assays) to 23vPPV challenge at age 2 years after 23vPPV booster at age 9 months in children primed with PCV. 8. The broad range of serotypes causing IPD in PNG necessitates continuing consideration of 23vPPV as a potential booster at age 9 months. 9. Serotype-specific B cell memory is an important aspect that we can now test to address immunological safety of PPV in children primed with PCV. 10. The Global Alliance for Vaccines and Immunisation (GAVI) and the World Health Organisation (WHO) have committed to the introduction of PCV for infants in GAVI-eligible countries (including PNG) using novel funding mechanism. In PNG, the introduction of a PCV is planned for 2013.