United States infected twice with COVID-19 shows there is much yet to learn about immune responses and also raises questions over vaccination, scientists said on Tuesday.The 25-year-old from Reno, Nevada, tested positive in April after showing mild symptoms, then got sick again in late May with a more serious bout, according to a case report in the Lancet Infectious Diseases medical journal.
240,000 Canadians applied for new coronavirus benefit on 1st day, Trudeau says The report was published just hours after U.S.