covid-19November 20, 2020 ‘We cannot rest’: Despite promising Covid-19 vaccine results, trials must continue Recent encouraging results from late-stage trials of Covid-19 vaccine candidates have led to an unexpected complication: a drop-off in volunteers in other vaccine studies. Related posts U.K.'s Johnson launches mass testing…Do you need a Covid-19…What's behind workers' hesitation to…Fully vaccinated people can travel…Younger Latino men are Covid's…Salmonella infections in eight states…Salmonella infections in eight states…The U.S. isn't losing to…Virus-killing robot tested for use…In Covid fight, Cuba touts…