British Prime Minister Boris Johnson gives an update on the coronavirus pandemic during a virtual news conference Monday in London. Johnson and other world leaders signed a letter calling for greater international cooperation in fighting future pandemics.

LONDON, ENGLAND – MARCH 29: Britain’s Prime Minister, Boris Johnson gives an update on the coronavirus Covid-19 pandemic during a virtual press conference in the new £2.6million No9 briefing room on March 29, 2021 in London, England. Outdoor sports and up to six people or two households can gather as from today in the first stage of England easing lockdown measures. (Photo by Hollie Adams – WPA Pool/Getty Images)