Edward Parker is an Assistant Professor in Systems Biology at the London School of Hygiene & Tropical Medicine. His work explores why vaccines are more effective in some individuals than others, with an emphasis on the potential role of the gut microbiome. During the pandemic, he developed and continues to maintain the LSHTM Vaccine Centre’s COVID-19 vaccine tracker. His current MRC secondment employs electronic health records within the OpenSAFELY platform to explore variation in COVID-19 vaccine uptake and performance among immunosuppressed populations