Prof Ravi Gupta, a member of the New and Emerging Respiratory Virus Threats Advisory Group (Nervtag), told BBC Radio 4’s Today programme there had been “exponential growth” in new cases, with the variant first detected in India accounting for three-quarters. Asked if the third wave had begun, Gupta replied: “Yes.” He added: “Of course, the numbers of cases are relatively low at the moment – all waves start with low numbers of cases that grumble in the background and then become explosive – so the key here is that what we are seeing here is the signs of an early wave. “It will probably take longer than earlier waves to emerge because of the fact that we do have quite high levels of vaccination in the population, so there may be a false sense of security for some time, and that’s our concern.”