covid-19February 21, 2021 Race against virus variants in South Africa is lesson for global vaccine planners “What we are going to see is a cat-and-mouse game between virus changing and then vaccine manufacturers having to quickly change their vaccines.” 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…