The Imperial College London scientist said it was “almost inevitable” that daily infection rates will hit a record 100,000 within weeks, and said the pandemic could spike at more than 200,000 positive cases a day.
Cabinet minister Robert Jenrick agreed that the wave driven by the Delta variant of Covid-19 will be “challenging” and could last into September, but said the government would do “everything we can” to avoid further lockdown restrictions.
Prof Ferguson told BBC1’s Andrew Marr Show that “success” in the current wave would be “keeping hospitalisations at around 1,000 a day and then declining, case numbers maybe peaking a little over 100,000 a day and then slowly declining.”
And he said that there was likely to be a large increase in numbers suffering the symptoms of long Covid, such as extreme fatigue, weakness, headaches and “brain fog” for three months or more.
“We’re seeing very high infection rates now,” said Prof Ferguson. “We’ve seen the impact on schooling. We’ll have probably an impact too on long Covid rates.
“We know now that probably around a quarter of people who get symptomatic Covid have those symptoms for a long period of time.
“We are at about a million people with long Covid, on Office for National Statistics numbers, we could go up another half a million on top of that.”
Prof Ferguson said there was considerable uncertainty about precisely how many people will be caught by the Delta variant over the coming weeks, but made clear there was little doubt that the number of daily cases would far surpass the 60,000-plus peak experienced in January.
“I think it’s almost certain we’ll get to 1,000 hospitalisations per day,” he told Marr. “It’ll almost certainly get to 100,000 cases a day.
“The real question is, do we get to double that or even higher? And that’s where the crystal ball starts to fail. We could get to 2,000 hospitalisations a day, 200,000 cases a day, but it’s much less certain.”
Infections at this level would place a “significant burden” on the health system, even though vaccination has reduced the link with serious illness and death, he said.
A level of 2,000 hospital admissions a day would be “roughly half what we got to before Christmas with the second wave”, said Prof Ferguson.
“There you are talking about major disruption of services and cancellation of elective surgery and the backlog in the NHS getting longer and longer.”
Prof Ferguson said it looked like people currently being admitted to hospital were not as severely ill as those in December and January, with the mortality rate “much, much lower”.
“Still, if you have enough cases you can still have quite significant burden on the healthcare system,” he said.
He added: “Fundamentally, this will be a different wave from the previous two.
“The previous two peaked because we introduced lockdown measures, and that’s the only reason.
“This time, if we don’t have to change course, then it will peak because herd immunity is being reached, and then it overshoots and you still get infections beyond that point, but the epidemic will be in decline.”
Responding to Prof Ferguson’s warnings, housing secretary Robert Jenrick told Marr: “I think we have to be honest with ourselves that we're going to see a significant rise in the number of cases, and the number of people going into hospital.
“As Professor Ferguson said, it's likely that this wave - that we've known about since at least the beginning of the year - isn't going to peak until late August, possibly even into September.
“So there's going to be some challenging days ahead.
“It is true, however, that we've significantly weakened the link between cases and serious illness. The last time we had cases at the level we do today, the number of people dying from the virus was 30 times the number it is today.”
The housing secretary added: “Of course, we will do everything we can to avoid having to impose further restrictions and that's why we're urging the public to exercise caution to exercise good judgement and common sense, and to go about daily life in a sensible careful way, and to do things gradually, rather than rushing back to normality on Monday.”
Mr Jenrick said the government was “very worried” about long Covid and was today allocating a further £20m for research into the “cruel and debilitating” condition.
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