LONDON, ENGLAND - MARCH 17: British Prime Minister Boris Johnson gives a press conference about the ongoing situation with the coronavirus (COVID-19) outbreak inside 10 Downing Street on March 17, 2020 in London, England. For most people, the new coronavirus causes only mild or moderate symptoms, such as fever and cough. For some, especially older adults and people with existing health problems, it can cause more severe illness, including pneumonia. (Photo by Matt Dunham - WPA Pool/Getty Images)