Dr. Visser has extensive research expertise in tropical medicine and infectious diseases, with a focus on malaria, tuberculosis (TB), and HIV. Their clinical and research interests include the study of vaccinations for immunocompromised patients, particularly people living with HIV (PLWHIV), as well as individuals receiving immunosuppressive treatments or living with immunosuppressive conditions. Dr. Visser's work is dedicated to improving prevention strategies and vaccination efficacy in these vulnerable populations.