Setting aside the bitter election battle, former US president Barack Obama on Friday sent a message of support to White House successor Donald Trump and his wife Melania, who have both contracted Covid-19. At the start of a fundraising event with vice presidential candidate Kamala Harris, Obama said: "Although we're in the midst of a big political fight, and we take that very seriously, we also want to extend our best wishes to the president of the United States, the first lady."