Prof Whitty’s warning came as experts said the UK was now at the beginning of a third wave of the virus, and that the return of lockdown restrictions could not be ruled out, with the possibility of as many as 1,200 deaths a day at the peak.
A study commissioned by the government found that coronavirus cases are “rising exponentially” across England and doubling every 11 days, driven largely by younger, unvaccinated age groups.
Health secretary Matt Hancock announced that from Friday, 18-year-olds in England will be able to book vaccinations as part of a drive to protect all adults against Covid-19 before the delayed end to lockdown restrictions on 19 July.
As the NHS passed the milestone of administering first doses of vaccine to four-fifths of all adults in the UK (42,216,654 people) and second doses to 58 per cent (30,675,207), Mr Hancock said the country was “entering the final furlong in our race against the virus”.
But Prof Whitty said that this was unlikely to be enough to prevent “a third surge” of Covid in the coming weeks and a further wave in the autumn and winter.
Speaking to the NHS Confederation, the chief medical officer for England said that the current upsurge in cases of the Delta variant first identified in India will “definitely” translate into further hospitalisations and deaths.
And he added: “My expectation is that we will get a further winter surge – late autumn-winter surge.
“And that’s because we know that winter and autumn favour respiratory viruses, and therefore it would be very surprising if this particular highly transmissible virus was not also favoured. So we’ll get the current wave – an exit wave – then I do think most people think that there will be further problems over the winter.
“How big they will be I think is uncertain. That partly depends on [whether] we get any variants that can evade vaccines better, and on how the current wave passes through the UK.”
Prof Whitty said it would be “very surprising” if the coming winter was as bad as the one just gone, which was the worst that anyone in the NHS could remember.
But he said: “I think we need to be aware of, and brace for, the fact that the coming winter may well be quite a difficult one.
“We have to just be aware that Covid has not thrown its last surprise at us.”
Imperial College epidemiologist and government adviser Professor Neil Ferguson said that the third wave of Covid-19 had already begun in the UK, and that it would “inevitably” result in a rise in hospitalisations and deaths.
Prof Ferguson, who sits on government advisory group Sage’s modelling sub-group SPI-M, said there was not yet enough data to make firm predictions about the scale of the third wave, but that he would expect at least 100 deaths a day at its height, and possibly a similar daily death toll to the 1,200 seen during the winter peak.
“The uncertainty spans the range [from] having a third wave which maybe is 100-200 deaths a day at peak to something which is at the scale of what we went through in January,” he told a media briefing.
Data from nearly 110,000 swab tests submitted to Imperial’s React study showed that Covid infections across the UK increased 50 per cent between 3 May and 7 June as the country struggled to combat the rise of the Delta variant.
The bulk of infections were found among children aged between five and 12, as well as younger adults aged between 18 and 24, with infections among these age groups five times higher than in over-65s, said researchers.
The study showed a “rapid switch” in recent weeks between the Alpha variant first detected in Kent and the Delta variant, with the latter now accounting for up to 90 per cent of all Covid cases.
Scientists said the findings of the React study suggest that the expansion of the vaccine programme to those aged 18 and above “should help substantially to reduce the overall growth of the epidemic”.
But SPI-M chair Professor Graham Medley said it was “not impossible” that restrictions removed over the past few months would have to be reintroduced.
“I find it hard to believe that we’d have to go backwards from where we are,” said Prof Medley. “But it’s not impossible that at some point the government will say, ‘Actually this number of hospitalisations is beyond what we want to live with’ … and put in place restrictions.”
Latest official figures showed that 58,830 people had tested positive for coronavirus in the UK over the past seven days – up almost 34 per cent on the previous week.
A total of 11,007 new cases and 19 daily deaths were reported on Thursday. The death toll of 78 over the past seven days was up 42 per cent on the 55 recorded in the previous week.
And hospitalisations were also shown to be rising fast, with the figure of 1,324 patients admitted over the past seven days being 43 per cent higher than the previous week.
Medicine professor Paul Hunter, of the University of East Anglia, said the latest data suggested that the rate of increase in cases had declined since the Imperial study was conducted earlier in the month.
“Although it is still a little too early to be sure, the rate of growth in the epidemic in the UK seems to have slowed somewhat in the past few days,” said Prof Hunter.
“On balance, it does appear that the epidemic in the UK may no longer be increasing exponentially. Clearly the epidemic is not yet over; case numbers are still increasing but just rather more slowly than a week ago.”
One reason for the increase easing off may be the presence of antibodies from previous infections among members of the age groups worst hit by Delta, he suggested.
And he said there were “significant grounds for optimism” that the third wave would not kill anywhere near as many as seen in the winter.
“I am increasingly optimistic that this latest extension to restrictions should be the last,” said Prof Hunter. “Although we are likely to see case numbers increase in future, we are unlikely to see a surge of cases, hospitalisations and deaths anything like what we have seen this last winter again.”
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