The doctor who was once the country's most senior medic has told the UK Covid-19 Inquiry that lockdown "damaged a generation" of young people.
In an emotional evidence session, Professor Dame Sally Davies, the former chief medical officer (CMO), also apologised to families who lost loved ones during the pandemic for their "harrowing" experiences.
Dame Sally, who was England's CMO from 2011 to 2019, said she was upset by the impact of Covid and lockdown policies on children and young people despite being in favour of the first national shut down.
"I mean it's clear that no one thought about lockdown," she told the inquiry. "I still think we should have locked down the first time or a week earlier. But during that, we should have thought further. The damage I now see to children and students from Covid and the educational impact tells me that education has a terrific amount of work to do.
"We have damaged a generation and it is awful, as head of a college in Cambridge, watching these young people struggle, and I know, in pre-school, they haven't learned how to socialise and play properly, they haven't learned how to read at school, we must have plans for those."
Dame Sally, who was also the chief scientific adviser for the Department of Health between 2004 and 2016 apologised and expressed regret that plans to prepare for a pandemic had not examined the impact on civil liberties.
Asked if the possibility of a lockdown wasn't planned for and not foreseeing this was one of the more notable failures of pandemic planning, she said: "I'm sorry we didn't plan for that. I would prefer to have planned to not get us to that stage. But we didn't recognise that it could."
Several senior figures including David Cameron, the former prime minister, have admitted the UK focused on the wrong pandemic, worrying about influenza instead of a new emerging virus.
Dame Sally said she put up some "challenge" to what she described as "groupthink" around flu by raising the alarm about Mers and Sars outbreaks abroad, but wished that she had done more.
Appearing to hold back tears, she told the Inquiry: "Maybe this is the moment to say how sorry I am to the relatives who lost their families.
"It wasn't just the deaths, it was the way they died. It was horrible. I heard a lot about it from my daughter on the front line as a young doctor in Scotland.
"It was harrowing and it remains horrible."
She said that, during the pandemic, she now believed the Government would have benefited from weighing up the wider impact of measures and listening to people like economic experts, not just scientists.
"It seemed to me that sitting outside at all, which gives you some advantages, in thinking and challenging of course, that what we needed to do was balance the biomedical model, with the economic and social that ministers and Government need to be presented.
"Not only with the biomedical advice, but also what's the impact on the economy, on the social cohesion of our community, and on education. And so we needed as a nation, a second group advising on all of that."
The Inquiry continues.
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