Cécile van Els is an immunologist and an expert in vaccinology. She holds a PhD in transplantation immunology at Leiden University, the Netherlands. She aims to advance infectious disease control and One Health strategies by understanding protective B- and T-cell mechanisms against a variety of pathogens and by unravelling how and why effectiveness of specific immunity to certain infectious diseases may fail. Her expertise encompasses correlates of protection for HIV, measles virus, respiratory syncytial virus, influenza virus, mumps virus, mycobacteria, meningococci, pneumococci, B. pertussis and SARS-CoV-2. Working currently at the Center for Infectious Disease Control at the National Institute of Public Health (RIVM) as well as at the Veterinary Faculty of the Utrecht University, the Netherlands, it is her ambition to fuel vaccine innovation and trust by building bridges. She does so by connecting teams, topics, disciplines and institutions, by helping (young) scientists’ careers, and, during the COVID-19 pandemic, by translating vaccine science to policy makers and citizens.