On 9 March 2020, Martin Landray was studying the likely impact of Covid-19 as it started to sweep Britain. What was needed, he realised, was a method for pinpointing cheap, effective drugs that might limit the impact of the Sars-CoV-2 virus that was filling UK hospitals with ­dangerously ill patients.

Within 10 days, Landray - working with Oxford University colleague Peter Horby - had set up Recovery, a drug-testing programme that involved thousands of doctors and nurses working with tens of ­thousands of Covid-19 patients in UK hospitals.

Trials were carried out in wards crammed with sick individuals, and these quickly showed that several overhyped medicines such as the antimalarial drug hydroxychloroquine were ineffective.

At the same time, dexamethasone, a cheap treatment for inflammation and arthritis, was found to reduce deaths by a third among patients on ventilators, a discovery that saved more than a million lives across the planet.

Recovery was one of the UK's greatest scientific triumphs in the battle against Covid, though Landray remains cautious. "It was a great achievement but I have to say we were lucky that we got approval to set up the programme so quickly," he told the Observer.

"I worry that this would not happen again when the next pandemic arrives. We could end up with a lengthy, committee-driven process that would be too slow and we would not get another Recovery. We have not learned our lessons."

It is a view shared by many other scientists. Britain may have triumphed with its Recovery programme and its speedy introduction of vaccines but the nation today shows alarming signs of forgetting the scientific lessons it learned during the pandemic. It is a point stressed by Prof Adam Finn of Bristol University.

"In terms of public health decisions, the main lesson we learned in 2020 is straightforward: when you get a pandemic, don't assume it's going to be like the last one. Five years ago, everyone expected the next pandemic would be flu, and so models assumed we had to shut down schools and keep children at home because they would be the ones spreading disease.

"That would have been true for flu but it wasn't for Covid. Young people were not disease spreaders and, wrongly, were kept apart. They paid an unnecessary price because we had made false assumptions."

It was a key lesson but Finn said he now worried the nation was already forgetting what it had learned during Covid. "It's already beginning to happen, not just in the minds of the public, but also in the minds of the scientific community. The memories and lessons - such as the mistake of the prolonged closure of schools - are being lost. We actually need to record what happened with care so that our past experiences can guide us when this happens again. Merely holding inquiries in order to castigate people for getting things wrong is not enough."

Criticism of the processes by which scientists advise government was also voiced by Prof Mark Woolhouse of Edinburgh University. "I don't think the scientific advisory system worked well throughout the pandemic," he told the Observer. "There were too many mistakes made, and I think we need to change how we do that. We need a better way of sampling scientific evidence and scientific opinion, and a better way of turning it into advice. We need to ask more scientists and distil their views into advice."

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Woolhouse also criticised the decision to delay the large-scale deployment of lateral flow tests. "The scientific advisory system did not embrace this as a technology and so it was not rolled out as it could have been in late 2020 when it could have played a key role in avoiding the next lockdown. Instead, we had to wait another year for it to be used in a widespread manner when it played a key role, along with vaccines, in the battle against the arrival of Omicron variant," added Woolhouse.

Prof Sir Andrew Pollard, director of the Oxford Vaccine Group, warned that institutional knowledge in the UK about what to do in the event of a new pandemic was now on a precipice.

"We are still not ready today to protect the population within 100 days of onset for most pandemic scenarios and we are not spending enough on health security to get there any time soon.

"The risk to society from pandemics should be taken more seriously as the last, relatively trivial, low mortality pandemic still caused a global shock. The next could change the world as we know it."