People wear masks while riding on the subway as cases of the infectious coronavirus Delta variant continue to rise in New York City, on August 2. — Reuters LOS ANGELES: With a new wave of Covid-19 infections fueled by the Delta variant striking countries worldwide, disease experts are scrambling to learn whether the latest version of coronavirus is making people — mainly the unvaccinated — sicker than before. The US Centres for Disease Control and Prevention warned that Delta, first identified in India and now dominant worldwide, is “likely more severe” than earlier versions of the virus, according to an internal report made public on Friday.