His main areas of interest are: (i) immunological memory to malaria parasites in historically infected individuals, (ii) host factors responsible for increased susceptibility to malaria in a small proportion of children that experience excessively more malaria than expected, and iii) the mechanisms responsible for controlling parasite growth and inflammation in semi-immune adults following experimental infections. These studies are providing the much-needed insight into how we can induce protective immune responses to P. falciparum malaria by vaccination in the background of the immune-regulatory state induced by natural exposure in endemic areas. Upon the introduction of Covid-19, he was quick to use his experience and skills to initiate a project on Covid-19 immunology - understanding Sars-CoV-2 immunology in the African population. Furthermore, his group has been involved in the response to the pandemic in Kenya with involvements in Covid-19 testing, and sequencing of Sars-CoV-2 viruses.