LONDON - It is a long road back to business as usual from the COVID-19 pandemic, the head of Britain's coronavirus genome sequencing effort told Reuters, adding she was on alert for new mutations to the Delta variant that is sweeping the world.

Prime Minister Boris Johnson has ended England's coronavirus lockdown, saying Britain must cautiously learn to live with the virus, and that a quick vaccine rollout has allowed for a summer reopening.

Sharon Peacock, chair of the COVID-19 Genomics UK (COG-UK) consortium, said that the process of returning to normal would be slow, due to uneven vaccine rollouts globally.

"It's quite a long path to get back to business as usual," she told Reuters, adding that clear global surveillance for new variants and co-ordination on the best vaccine against what is coming up, as there is with flu, would be needed.

"I see that as quite a long journey. So it's not going to be one day that we wake up and say right we're going to live with COVID-19 and everything's okay. I think there's still a lot of groundwork to be done."

Britain has launched a New Variant Assessment Platform Programme to share its genomics expertise globally.

The variant of biggest concern at the moment is the Delta variant, which Peacock characterises as the "fittest and fastest variant yet".

Delta is highly transmissible and has also been shown to reduce the effectiveness of the first dose of COVID-19 vaccines, and could become even more troublesome.

"There's quite a lot of new mutations in the Delta variant, and so that's being watched very carefully. There's no reason at this point in time to be alarmed about that," she said.

"But we have to continue to watch for a particular sort of variant of a variant if you like, that is associated with, for example, even more spread... That's under constant monitoring at the moment."

(Reporting by Alistair Smout; editing by Guy Faulconbridge) ((alistair.smout@thomsonreuters.com; +44 207 542 7064; Reuters Messaging: alistair.smout.thomsonreuters.com@reuters.net))