Helen is a scientist with an interest in vaccines. She has been investigating a range of vaccine-related topics for twenty-three years and settled on vaccine effectiveness and vaccine safety. As co-director of the Global Vaccine Data Network, she leads the largest vaccine safety studies ever undertaken across seventeen countries. She is the previous chair of the WHO Global Advisory Committee on Vaccine Safety and is currently shortlisted for the Nature Awards for Driving Global Impact. Helen has a science blog where she often addresses vaccine misinformation, and most recently, she has been swamped with questions about COVID-19 vaccine myths.