While many hoped the pandemic was over, scientists were more surprised the Delta variant of COVID-19 hadn't been overtaken by another one. 

Unfortunately that has now happened and Emma Keeling speaks to virologist Jeremy Rossman about how worried people should be about the Omicron variant and also takes a look at Japan where cases have dropped dramatically from their peak after the Olympics. Could a Japanese scientist's theory be right that the virus has mutated so much it's driven a strain to extinction?