The UK lacked the resources to scale up its response to Covid-19 and politicians need to make “explicit” decisions about how much money they devote to preparing for future pandemics, England’s chief medical officer told the government’s Covid inquiry on Thursday.

Sir Chris Whitty told the hearing that diagnostic ability was essential in any epidemic and the UK had responded well to the initial small number of cases. But he added that it had lacked the ability to accelerate its response in diagnostics and other areas such as personal protective equipment.

“It’s the scaling up which, in my view, was a weakness that was demonstrated during the early phase of Covid,” Whitty said.

He added that maintaining capacity between pandemics required investment and politicians would need to choose “between having an insurance against future events and, for example, investing in pressures in the NHS during winter. That is a choice and I think it has to be made explicit,” he said.

The chief medical officer also suggested that although expert committees such as the scientific advisory group for emergencies (Sage) had worked well during the epidemic, with “a reasonable balance between coherence and challenge”, there was a need for more “radical” thinking by scientific advisers between public health emergencies.

He admitted that it would not have been feasible for scientific experts to have prepared for the possibility of a national lockdown without being instructed to do so by ministers. The mandatory quarantine that Britons were subject to at the height of the pandemic was “the very big new idea” that had emerged through the crisis and “a very radical thing to do”, he said.

“I would have thought it would be very surprising, without this being requested by a senior politician or similar, that a scientific committee would venture, between emergencies, into that kind of extraordinarily major social intervention with huge economic and social ramifications,” he said.

Whitty added that most overseas observers would judge the UK scientific response to have been “very strong by international standards” even though there were “other areas people might be more critical on”, he noted.

Sir Patrick Vallance said practical expertise in vaccine manufacturing would be important for future resilience © James Manning/PA Wire Sir Patrick Vallance, the government’s chief scientific adviser until April 2023, followed Whitty into the witness box and backed up several of his colleague’s points. He said the government had to be clearer about the risks of spending money on things that might not be needed.

He pointed out that while the Vaccines Task Force had been one of the success stories of the pandemic, when it was set up in the spring of 2020 he thought it “possible, even likely” that its mission would fail.

“If it had failed, the National Audit Office would have probably written a report saying what an outrageous waste of money it was,” he said.

Covid-19 also showed how important the country’s industrial base was for pandemic preparedness, Vallance said. “By 2020 UK vaccine manufacturing had almost gone . . . while we didn’t have a diagnostics industry on any scale, which made it very hard to scale up testing.” Germany, with a larger diagnostics sector, had been able to scale up much faster.

Vallance said practical expertise in vaccine manufacturing would be important for future resilience. “Don’t dream that you can have a vaccine factory sitting there waiting for a pandemic,” he said. “It’s going to be staffed by people who don’t know how to make vaccines.”