Ifedayo is a consultant pediatrician and infectious diseases epidemiologist. Prior to his arrival at the programme, he worked for a decade at the United Kingdom's Medical Research Council Unit, The Gambia where he led clinical and field activities for the Tuberculosis (TB) epidemiology research including the TB case contact platform. His research interests there were delivery of TB diagnostics and care, assessment of novel diagnostics for TB infection and disease including biomarkers for disease and protection, and systematic reviews. In his last MRC role, he was the principal investigator on a Â£2.6million TB Epidemiology projects portfolio that included a nationwide TB prevalence survey and a community randomised trial to assess the impact of an enhanced TB case finding strategy on TB notification. He works full time at the Kilifi KEMRI-Wellcome Trust Research Programme on the Pneumococcal Vaccine Impact Study (PCVIS), and the Kilifi Vaccine Assessment Platform. He is also with the Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine. His current research interests are vaccine effectiveness studies, vaccine monitoring including issues of coverage, timeliness, and equity.