Boris Johnson, the former Prime Minister of Britain, struggled to understand much of the science during his time in office, according to testimony from his former chief science adviser Patrick Vallance at a public inquiry into the COVID-19 pandemic on Monday. Vallance noted that he and others encountered repeated difficulties in getting Johnson to understand the science, but also pointed out that leaders in many countries have faced similar problems understanding scientific evidence and advice. The inquiry will continue with further testimony expected before Christmas.