Carriage prevalence and antibody functionality after full and fractional doses of pneumococcal conjugate vaccine (PCV13 and PCV10) in a 2 prime plus boost schedule compared to a control arm of a 3 primary dose series in Kenyan infants

Principal investigator: Katherine Gallagher
Institution: London School of Hygiene and Tropical Medicine; KEMRI-Wellcome Trust Research Program, Kilifi, Kenya
Co-investigators: Anthony Scott, David Goldblatt

Start date: July 2018

Worldwide, over 50 LMICs to date have introduced PCV with the support of Gavi, the Vaccine Alliance; however, as economies grow and countries transition out of Gavi support, the sustainability of their PCV programmes is at risk. PCV is currently the most expensive vaccine in the routine immunisation schedule in Gavi-supported countries. The project aims to assess the functionality of the antibody response after full, or fractional doses of PCV13 or PCV10 by using an opsonophagocytic assay. The MPRU will enable a comparison of the immunogenicity and carriage impact of a fractional dose, given in the 2p+1 schedule, against the current Kenya standard (a 3p+0 schedule) by adding one additional trial ‘arm’ of study infants. This group will act as a contemporaneous 3p+0 control arm for carriage and immunogenicity assessments, against which the full and fractional doses of vaccine delivered in a 2p+1 schedule in the trial can be assessed.

Aims and Impact

To determine whether fractional doses of PCV13 or PCV10 provide sufficient protection protection against S. pneumoniae, where if true, would reduce vaccination cost and thereby incentivise LMICs to continue PCV vaccination programmes post-Gavi.