As weekly Covid case rates doubled in Bolton – the town worst hit by the B1.617.2 strain – efforts to clamp down on the variant were stepped up in Bedford, Burnley, Leicester, Kirklees, North Tyneside, Glasgow, Moray and Hounslow in west London.
But test and trace chief Dr Jenny Harries insisted that the fight against the Indian variant was not lost, despite Public Health England figures showing that 135 areas of England saw rising case rates in the week to 15 May.
Boris Johnson also said there was “increasing confidence” that vaccines were effective against the strain, in a boost to hopes that remaining lockdown restrictions can be lifted in England as planned on 21 June.
However, epidemiologist Professor Neil Ferguson, a member of the government’s Scientific Pandemic Influenza Modelling Group (SPI-M), said that the target reopening date was “very much in the balance” because of the surge in variant cases.
The scientist said the importation of the new strain showed that the system of home quarantine for people arriving from abroad – now applied to most countries in the world under the government’s “amber list” rules – “basically didn’t work”.
Health secretary Matt Hancock said that increasingly sophisticated biosecurity surveillance techniques – including analysis of wastewater from toilets – was allowing areas of concern to be identified much more swiftly than the mutant strain that emerged in Kent in the autumn.
He announced in parliament that 2,967 cases of the Indian variant have now been confirmed in the UK – up from about 1,300 at the weekend. Some 25 people are now in hospital in Bolton with Covid-19 symptoms, with the majority of patients unvaccinated. But Mr Hancock said that “nearly 90 per cent” had not had two vaccine jabs, suggesting that some individuals are in hospital despite having had both doses.
Bolton topped the Public Health England list of areas with the fastest overall rate of growth in Covid-19 cases, with 920 new positive tests in seven days. It was followed by Indian variant hotspots Bedford, Blackburn and Burnley, fuelling scientists’ concern that the new strain is much more infectious than earlier types and could become dominant across the UK if not contained.
Deputy chief medical officer Jonathan Van-Tam said that it was unlikely to become clear until next week exactly how much more transmissible the new variant is than the Kent strain. But he said most experts feel it will be “somewhere in the middle” of a range from a few percentage points to 50 per cent more infectious.
Prof Van-Tam told a Downing Street press conference that the UK was now facing “a straight race” between the transmissibility of B1.617.2 and the speed of NHS vaccination delivery. He stressed that transmission can be slowed down by testing and tracing and by “cautious behaviour” and urged people in areas of concern not to “tear the pants out of it” when enjoying the new freedoms available since Monday.
“I would advise the residents in those areas to think very carefully about the freedoms they have,” he said. “Weigh up the risks and be very cautious.
Dr Harries, chief executive of the UK Health Security Agency, said Britain was in a “completely different place” compared to last year in terms of authorities’ ability swiftly to pinpoint outbreaks of variant virus.
“With that very precise testing, we can follow backwards, follow chains of transmission, undertake very enhanced contact-tracing so people are using shoe leather going door-to-door, working in these areas to support individuals, increase the testing capacity,” she said.
Indian variant cases in the Sefton area of Merseyside were now coming down in response to this kind of intervention, raising hopes that the variant can be contained, she said.
“It is not a game lost at all,” she said. “It’s very much one to fight and there are huge resources and huge amounts of effort, particularly from the public in all of these areas, and we should continue to do that.”
Mr Hancock told the press conference that almost 14,000 vaccines have been given in Bolton and Blackburn and Bolton since Friday, and over 26,000 in the last week the highest weekly total in these areas, while 75,000 extra tests have been delivered to these two areas alone, with 12 testing sites and a 100-strong team going door to door
“The advantage we have now, compared to the autumn when the Kent variant first arrived, is we just know so much more about it so much faster because of this extraordinary surveillance capability, so we could spot the rise in cases very, very early,” said the health secretary.
However, he held back from promising that further relaxations of lockdown would go ahead on 21 June, saying that a final decision would not be made until a week in advance.
Mr Hancock announced the launch of the world’s first trial of “booster” vaccines for Covid-19, with nearly 3,000 volunteers in the UK taking part in tests of seven possible jabs, backed by £19.3m of government money.
Results are expected in September, and will inform a large-scale booster programme pencilled in for the autumn.
“I urge everyone who has had both doses of a Covid-19 vaccine, and is eligible, to sign up for this study and play a part in protecting the most vulnerable people in this country and around the world for months and years to come,” said the health secretary.
More than seven in 10 British adults - 36.9m people - have now had their first Covid-19 vaccine, with almost two-fifths (39.6 per cent) having had both doses, the Department for Health and Social Care announced.
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies