Moderna CEO warns Covid-19 shots less effective against Omicron, markets tumble

Drugmaker Moderna set off fresh alarm bells in financial markets on Tuesday as the firm's chief warned that Covid-19 vaccines are unlikely to be as effective against the Omicron variant as they have been against the Delta version. Crude oil futures shed more than a dollar, the Australian currency hit a year low, and Nikkei gave up its gains as Stéphane Bancel's comments spurred fears that vaccine resistance could lead to more sickness and hospitalisations, prolonging the pandemic.