Coronavirus Q&A: Covid-19 has mutated - what happens now? Put your questions to our Science Editor Coronavirus has mutated into two strains, one which appears to be far more aggressive, scientists have said, in a discovery which could hinder attempts to develop a vaccine. Researchers at Peking University's School of Life Sciences and the Institut Pasteur of Shanghai, discovered the virus has evolved into two major lineages - dubbed ‘L’ and ‘S’ types. The older ‘S-type’ appears to be milder and