Prime Minister Boris Johnson faces a “very difficult” call on whether to drop restrictions on June 21 given the “more negative direction” of the data, according to a leading expert.
Professor Neil Ferguson, whose modelling was instrumental to the UK locking down in March 2020, said a “cautious” approach is needed as the Government balances the potential risks against a desire for normality.
He also said that news on the variant first identified in India is not positive as it could be anywhere between 30% and 100% more transmissible than the previously dominant Kent variant, also known as Alpha.
The full effect of easing some restrictions on May 17, such as indoor mixing in pubs, is yet to be understood and further data is required, Prof Ferguson added.
While Jeremy Farrar, director of Wellcome, said the June reopening “is perhaps the hardest UK policy decision of the last 18 months”.
For the Government, Communities Secretary Robert Jenrick said there is “nothing at the moment that suggests that we won’t be able to move forward” with the next stage of lifting restrictions on June 21.
Mr Johnson has come under pressure to move ahead with the June 21 unlocking – dubbed “freedom day” by some – given the huge uptake of Covid-19 vaccines in recent months.
But questions remain over the impact of the so-called Indian variant of Covid, also known as the Delta variant, on hospital admissions and deaths.
Dr Farrar said: “With cases and transmission increasing in the UK, and the new Delta variant now dominant, it’s crucial we wait and follow the data over the coming two weeks.
“The important question is whether rising cases are leading to an increase in severe illness and death.
“We know there is a time lag of several weeks between people first catching the infection, getting ill, going to hospital & ICUs, and dying.
“Which is why we need to wait until as close as possible to June 21, so we have all the data we need to make the right decision.”
He added that he is “cautiously optimistic” as the UK vaccine rollout had been a phenomenal success, but cautioned that vaccination rates must be kept up, and to use the time between now and June 21.
Dr Farrar also said the best way to protect the UK from future variants is through global vaccination.
Prof Ferguson told BBC Radio 4’s Today programme: “We’re certainly getting more data. Unfortunately, I mean, the news is not as positive as I would like on any respect about the Delta variant.
“The best estimate at the moment is this variant may be 60% more transmissible than the Alpha 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.”
Prof Ferguson said 60% is “a good central estimate” at the moment and noted that most people in hospital with the virus have not had a vaccination.
He added that data is still awaited on how much the Delta variant can evade the immunity which protects people against being admitted to hospital.
Asked about lifting restrictions on June 21, Prof Ferguson said: “I think the data is pointing this week in a more negative direction than it was last week, so it points towards the direction of being cautious.
“I think balancing, clearly, people’s desire – and there clearly is a built-up desire to get back to normal – against the potential risk is a very difficult judgment call.”
Asked what difference delaying the June 21 lifting of restrictions would make in terms of the scientific evidence, Prof Ferguson said: “We know at the moment that the Delta variant, the Indian variant, is doubling across the country about every nine days, with some variability place to place.
“But we haven’t fully seen the effect of what happened from May 17, step three, the relaxation of restrictions, come through into that data, so we expect that to accelerate even more.”
Mr Jenrick, appearing on the same programme, said: “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.”
Asked whether measures such as wearing masks and working from home could continue after June 21, Mr Jenrick replied: “Well, there are options that are clearly available to the Government.”
He added: “We set out within the road map what would be expected to happen at the next stage and we want to try to stick to that if we possibly can.
“All of us are moving everything we can to achieve that. But, of course, we keep these things under review and we’re also asking people to continue to exercise caution in their daily lives.”