Stephen Lockhart DM, FFPM, FMedSci. I qualified in Medicine from the University of Oxford in 1980. After working around the UK in hospital medicine and research, I joined the pharmaceutical industry in 1986. For over 30 years I have been engaged in global vaccine clinical R&D in Lederle, Wyeth, Emergent BioSolutions, sanofi-pasteur MSD, Pfizer and now as a consultant to several clients. I was involved with bringing some major vaccines to the clinic, including the first pneumococcal and the first meningococcal conjugate vaccines and the first modRNA COVID-19 vaccine, but have also learnt much from less successful developments. I have applied a wide range of clinical trials methodologies such as safety and immunogenicity phase 1, 2 and 3 studies, field efficacy trials, controlled human infection model efficacy trials and immunobridging trials. I am currently a consultant with Hurst Grange Associates, stephenlockhart@hurstgrangeassociates.co.uk.