Professor Andrew Hayward, an epidemiologist in the Sage group of scientists, said it is a matter of concern that the UK had higher rates of hospital admission and deaths linked to Covid than other European countries.
Downing Street on Monday acknowledged the coming months would be “challenging” but insisted there were no plans to reintroduce coronavirus restrictions in England despite rising cases.
For five consecutive days last week, the number of new Covid cases in the UK exceeded 40,000 per day.
New cases rose by 17 per cent last week compared to the previous seven days, the most recent weekly statistics from the website Worldometer show.
This puts the UK above the European average, which is a 13 per cent increase in Covid cases across all EU and non-EU European nations, according to the website that uses data sourced from governments.
The number of deaths in the UK linked to Covid have increased by 9 per cent over the same time. The European average is a 10 per cent rise.
Prof Hayward told BBC Radio 4’s World At One: “I think it’s concerning that we’ve got very high rates of infection and higher rates of hospitalisation and mortality than many of our European counterparts.
“Whenever we approach a winter period we expect respiratory virus infections to increase, so I think it’s very important that we go into that with as high a level of population immunity, especially in elderly and clinically vulnerable groups, as possible.”
He said waning immunity was “probably part of” the reason infections are currently high, adding there was “some evidence” protection against infection was beginning to wear off and “probably some evidence” protection against severe disease was falling to a lesser extent.
Prof Hayward added: “We shouldn’t be complacent because there is still huge potential for the NHS to come under a lot of pressure and for there to be a lot of unnecessary deaths.
“So we need to get the vaccination rates up and we need to be prepared potentially to think about other measures if things do get out of control.”
Figures from the Office for National Statistics on Friday showed coronavirus infection levels in England are getting close to the peak seen at the height of the second wave of the pandemic, and are mostly being driven by rates among schoolchildren.
Around one in 10 schoolchildren in Years 7 to 11 in England was estimated to have Covid in the previous week, the highest positivity rate for any age group, the figures suggest. But analysis by the PA news agency suggested there was low take-up of Covid-19 jabs among 12 to 15 year-olds.
In some areas the rate of vaccine uptake is as low as 5 per cent, while only 15 local authorities in England have managed to give a first jab to at least a quarter of 12- to 15-year-olds, data shows.
In Scotland, where young people can also receive doses of the jab in drop-in vaccination centres, the take-up is already over 50 per cent in half of local authority areas.
There have been calls for vaccines to be offered to under-16s in walk-in centres rather than in school in order to boost take-up in England.
Downing Street said the NHS was doing “everything possible” to contact people eligible for a third jab or booster shot, and children aged 12-15.
Prime minister Boris Johnson’s official spokesman acknowledged that winter would be “challenging” but insisted there were no plans to reintroduce coronavirus restrictions in England despite rising cases.
Under “Plan B” in the autumn and winter strategy, mandatory face coverings could be reintroduced in certain settings, along with the compulsory use of vaccine passports to get into nightclubs and other mass gatherings.
The Prime Minister’s official spokesman said: “There is absolutely no plan to introduce Plan B currently. We retain that capability if required if we believe the NHS is coming under unsustainable pressure.
“We are monitoring cases, as you know cases have increased recently. However, because of the protection from vaccines, we have substantially reduced that link between cases, hospitalisations and deaths which means numbers of hospitalisations - and indeed deaths - while they have increased slightly are not rising at the same rate.”
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