Ajit leads the NIHR Health Protection Research Unit in Respiratory Infections to protect the nation’s health of from the most serious respiratory infections: flu, TB and COVID-19. His patient-based research aims to understand the body’s natural mechanisms of protection against these lethal pathogens and the determinants of transmission. He translates his discoveries into innovative practical solutions to improve patient care and public health. These include the blueprint for a universal pandemic influenza vaccine, the mechanism of action of BCG vaccine, the first rapid TB blood test (IGRA), defining the infectious window of SARS-CoV-2 and its mode of spread in households, and the blueprint for variant-proof COVID vaccines. By devising the first IGRA-based national screening programme for latent TB in new migrants, Ajit has helped to halve England’s TB burden in recent years. He has raised >£40 million research funding and published >200 research papers, cited >12,000 times. Ajit supports the public’s engagement with science through his role as a Governor of The Science Museum Group, London.