Boris Johnson struggled to understand much of the science during his time as Prime Minister, according to former chief scientific advisor Patrick Vallance, who testified at the UK’s public inquiry into the COVID-19 pandemic on Monday. Vallance stated that he and others encountered repeated difficulties in getting Johnson to comprehend the science, but also mentioned that leaders in many countries faced similar problems in understanding scientific evidence and advice. Despite this, Johnson stepped down as Prime Minister in September 2022 following revelations of rule-breaking parties at his Downing Street residence during the pandemic and is scheduled to address the inquiry before Christmas.