Invited Speaker Lancefield International Symposium for Streptococci and Streptococcal Diseases 2025

Group A Streptococcus epidemiology and immunity in a high burden setting: insights from community studies in The Gambia (121596)

Thushan de Silva 1 2
  1. The University of Sheffield, Sheffield, SOUTH YORKSHIRE, United Kingdom
  2. Vaccines and Immunity Theme, MRC Unit The Gambia at LSHTM, Fajara, The Gambia

Group A Streptococcus (GAS) causes significant morbidity and mortality globally, yet data from high-burden, low-income settings remain limited. The talk will provide an overview of a programme of work in The Gambia, integrating clinical surveillance, microbiology, genomics and immunology data from longitudinal and cross-sectional community-based studies. The frequent importation of new GAS strains into households, combined with high strain diversity drives ongoing transmission and repeated exposure from early life. High incidence rates of skin carriage and pyoderma appear to play a central role in transmission and immune priming, particularly in young children. Through serological profiling, we characterise the evolution of antibody responses to conserved vaccine antigens and type-specific M peptides from birth through adulthood. These profiles provide insights into the timing and durability of naturally acquired immunity, and associations with protection from subsequent infection.