Meanwhile, a separate study from the University of Oxford showed a 17 per cent fall in diagnoses of childhood cancers in the months following the first lockdown.

Researchers found that those diagnosed during the pandemic were twice as likely to be admitted to intensive care before diagnosis, suggesting that the disease was more advanced, when survival chances are worse.

In addition, “alarming” NHS statistics showed that the number of children waiting for treatment for eating disorders has doubled in the past year. The official figures showed more than 2,000 children and young people waiting for treatment in September 2021, up from 860 in a year.

Experts said that the slew of data painted a devastating picture of the long-term harm inflicted on children and the problems being stored up for the future.

Dr Camilla Kingdon, the president of the Royal College of Paediatrics and Child Health, said that the study showed “very, very tiny numbers” of children dying from Covid.

Meanwhile, successive lockdowns and social distancing caused far greater consequences “through lost education, mental health, and other collateral damage”, she said, with much of the impact yet to be seen.

“There was a view that kids weren’t affected by Covid. But what we would constantly try to point out – and which some of this data shows – is actually, these are wider issues that are no less detrimental to children and may have a more long lasting impact actually, then the virus itself,” she said.

Children paid a ‘very, very heavy price’ for pandemic

Dr Kingdon said children had paid “a very, very heavy price” for the pandemic. And she said the impact was seen in many aspects of their health.

She warned: “You can also see it in community child health services, autism assessments, therapy referrals. 

“We’ve got a significant backlog to remedy as we move beyond the pandemic. Aspects of child health services have taken a hit because of the pandemic and there’s going to be a long process to catch that up.” 

Prof Russell Viner, a professor in adolescent health at University College London and an author of the paper on Covid cases, said: “When you look at this data together, it tells us that the indirect effects of the pandemic on children are likely to be significantly greater than the direct effects.”

Likening the actions taken in lockdown to “wrapping our children in cotton wool”, he warned that the steps taken in an effort to protect them now risked “suffocating their mental health”.

Dip in all childhood mortalities during pandemic

Official data show a dip in all childhood mortalities during the pandemic, with most flu and other respiratory infections wiped out by social distancing measures.

But Prof Viner said this was likely to “rebound at us” in coming years, with lack of exposure to everyday bugs leaving immune systems more vulnerable.

“The concern is that what we are doing is storing up problems for the future,” Prof Viner said.

The study of childhood cancers by the University of Oxford examined diagnoses among children and young people up to the age of 25, comparing the period from February 2020 to August 2020 with the same period in previous years.  

Overall, the numbers diagnosed with brain tumours, leukaemia, lymphoma, sarcoma and renal tumour fell by almost a fifth.

The study also suggests cases were detected far later than would normally be the case, with cases diagnosed during the pandemic twice as likely to be detected after admission to intensive care.

On Thursday, NHS data showed 5.8 million people on waiting lists for treatment, and the worst accident and emergency performance on record.