The first coronavirus lockdown would have come “much later” if the UK had not changed surveillance tactics to monitor cases in hospitals instead of in the community in the early stages of the crisis, a health chief has said.

The UK had “no tests left” as global health leaders encouraged countries to “test, test, test” during the pandemic’s early days, the UK Covid-19 public inquiry has been told.

Professor Dame Jenny Harries, chief executive of the UK Health Security Agency (UKHSA), said remaining tests were given as a priority to hospitals, which picked up more cases than anticipated.

Without this surveillance the UK may have gone into lockdown “much later”, she said.

The problem we had was we had 'test, test, tested' and we had no tests left... we prioritised the testing and the prioritisation of the testing is exactly the same prioritisation as WHO put out in its statement nine days later

Dame Jenny was quizzed about remarks she made during a Downing Street press conference in March 2020, after a decision was made to cease community testing.

She said the World Health Organisation (WHO)’s “test, test, test” directive was being made to low and middle-income countries before they had carried out a single test for Covid.

“The problem we had was we had ‘test, test, tested’ and we had no tests left… we prioritised the testing and the prioritisation of the testing is exactly the same prioritisation as WHO put out in its statement nine days later,” she said.

Dame Jenny said at the time it was important to “focus (testing) where it is clinically most valuable”.

She told the inquiry: “I fully supported WHO ‘test, test, testing’ but at this point we had no more tests.”

She added: “At this point, we had around 5,000 tests; they were prioritised into clinical treatment.

“And so everybody in hospitals, particularly in intensive care units, started to be tested.

“Now, if you look at the dates for this, the testing picked up more cases than was anticipated in hospitals.

So I think if we had not done this, we would have gone into lockdown much later

“And, by this time, you could then start to extrapolate back what that might mean for community infection rates.

“So this was a high-level surveillance system which then allowed us, with more certainty than was there, I think, which then led to the alerts to ministers and an early lockdown.

“So I think if we had not done this, we would have gone into lockdown much later.”

Dame Jenny was also asked about personal protective equipment (PPE).

In March 2020, she said the country had a “perfectly adequate” supply of PPE and while there were some “differential deliveries”, these had been resolved.

She said she later apologised for her remarks.

“I had been told that the new supply system for getting them around the country, so there wasn’t a differential distribution, was resolved,” she said.

“And that turned out to be not the case. And, in fact, I apologised as soon as I could when I was next on the stand about 10 days later.”

I recognise that, in retrospect, it feels wrong, almost, when we look back. We clearly were not in an exemplary position then

Dame Jenny also referred to international pandemic preparedness rankings made before the pandemic, when the UK was hailed as an “international exemplar” because it had a pandemic influenza stockpile.

Asked about pointing the gradings out in a Downing Street press conference in April 2020, she said: “The point I was trying to make here is that having a pandemic influenza stockpile of any sort whatsoever, which undoubtedly the country did, was considered – not by me, this is an external objective assessment – to have been a very high quality mark of a prepared country. Clearly the world will be reforming how it manages and assesses how good it is.

“I recognise that, in retrospect, it feels wrong, almost, when we look back. We clearly were not in an exemplary position then.”

Meanwhile, Dame Jenny said she never expected to be standing next to the prime minister giving press conferences in Downing Street.

She said she often was not given information before the press conferences, which often included questions about topics outside her brief at the time, when she was deputy chief medical officer for England responsible for health improvement.

Dame Jenny insisted it was not her job to defend Government policy during the press briefings.

What we have seen in the UK, in our own culture, and without mandation, is that people, if people have the information, then they will start to make choices themselves

She said in some press conferences she used “simpler, less scientifically detailed” language but still tried to get the public health message across.

Meanwhile Dame Jenny told the inquiry that the UKHSA is trying to build data dashboards, similar to ones used during the pandemic, so the public can see what is happening and “make their own choices”.

“What we have seen in the UK, in our own culture, and without mandation, is that people, if people have the information, then they will start to make choices themselves.

“It is important to be transparent with the information and to share it.”

Dame Jenny will continue giving evidence on Wednesday.