The transmissibility advantage of the B.1.617.2 variant first identified in India might be a little lower than first feared, a leading British epidemiologist said, but vaccines might be less effective at limiting its spread, Reuters reports.

Prime Minister Boris Johnson had warned that the emergence of the variant might derail his plans to lift England's lockdown fully on June 21. Johnson said that if the variant was only marginally more transmissible than the dominant Kent variant, then easing could continue as planned, but a significant transmissibility advantage might force him to reconsider the plans.

“There's... a glimmer of hope from the recent data that, whilst this variant does still appear to have a significant growth advantage, the magnitude of that advantage seems to have dropped a little bit with the most recent data,” Neil Ferguson, an epidemiologist at Imperial College London, told BBC radio.

Ferguson, who is member of the government's Scientific Advisory Group for Emergencies, said that it was tricky to immediately determine by how much how the B.1.617.2 outcompetes the Kent variant, and more data was needed.