Genome-wide association study of conjugated pneumococcal vaccine antibody responses in South African infants

Abstract Pneumococcal conjugate vaccines have substantially reduced global mortality, yet the genetic basis of vaccine-induced immunity is unclear. We analysed host genetic determinants of PCV7-induced IgG responses in 1017 South African infants. No genome-wide significant associations were identified, including at the HLA locus. In contrast to protein vaccines, where HLA strongly shapes responses, PCV7 responses appear less constrained by HLA-mediated antigen presentation. This reduced constraint could partially explain their consistent effectiveness across diverse populations.