The Delta variant of coronavirus, first discovered in India, is anywhere between 30% to 100% more transmissible than the previously dominant Alpha (or Kent) variant, according to Prof Neil Ferguson, whose Covid modelling was key to the UK’s first lockdown.
Ferguson is a leading epidemiologist at Imperial College London who advised the government at the beginning of the pandemic.
He told BBC Radio 4’s Today programme: “We’re certainly getting more data. Unfortunately, the news is not as positive as I would like in any respect about the Delta variant. The best estimate at the moment is this variant maybe 60% more transmissible than the Alpha [Kent] variant.
“There’s some uncertainty around that depending on assumption and how you analyse the data, between about 30% and maybe even up to 100% more transmissible.”
It comes as the date of lifting lockdown approaches, with 21 June the proposed time when the government will remove “all legal limits on social contact”, although some social distancing and mask-wearing rules will remain.
The communities secretary, Robert Jenrick, said there was still “nothing at the moment that suggests that we won’t be able to move forward” with the next stage of lifting restrictions.
He told Radio 4’s Today programme: “We’ve got a further 10 days until we are going to make that decision on or around June 14, so during that period we’ll see where are we with hospitalisations, with deaths, where are we with the vaccine rollout – we’re doing everything we possibly can to expedite that – and then at that point, we’ll make our final decision.”
Dr Mike Tildesley, a member of the scientific pandemic influenza modelling group government advisory panel, said the June 21 proposed reopening in England will be a “really difficult decision”.
He told BBC Breakfast: “I think the question the government needs to answer, and I can’t answer this, is: if we show that cases may rise, and of course, hospital admissions and deaths may rise over the coming months, what kind of rise in those the government can cope with to allow society to reopen?
“Of course, if you delay that date then those rises will not be as severe. So, that’s the trade-off the government are going to have to have in terms of if they are willing to open up knowing there may be a rise if they delay that may lessen the rise, but of course then that impacts businesses all around the country, so I think it’s a really difficult decision.”
He said his “hope and belief” was that hospital admissions would not rise on the same scale as they did in January.
Matt Hancock, the health secretary, said there were encouraging signs vaccines were breaking the link between infections and hospital admissions, as Public Health England announced zero daily reported Covid deaths for the first time since last summer.
Boris Johnson is understood to be optimistic about the current data but a No 10 source said the next few days would be crucial to assess the impact of the unlocking that took place from 17 May – though early data did not show significant cause for alarm.
