Boris Johnson has admitted there are many things he wishes he had done differently to tackle the Covid-19 pandemic as the UK marks a year since the first lockdown and remembers the 126,000 people who have died so far. At a Downing Street press conference, England’s chief medical officer, Prof Chris Whitty, also conceded the country had endured “a bad outcome”, but the prime minister once again refused to commit to a public inquiry to look at the decisions taken by the government over the last year. Rebuffing calls for an inquiry, he said lessons would be learned at the right time. He did announce there would be “a fitting and a permanent memorial to the loved ones we have lost and to commemorate this whole period”. The prime minister later prompted an outcry from opposition MPs after telling a meeting of his own backbenchers, in remarks he quickly retracted, that the UK’s “vaccine success” was “because of greed my friends”. During the No 10 briefing both Johnson and Whitty repeated stark warnings about the risk of a third wave of infections in the UK after steep rises in European countries. Whitty said there would “definitely be another surge” of Covid cases despite the vaccine programme, saying there would be “bumps and twists on the road” ahead, a hint at the struggles the UK has faced over new variants and the looming threat of export bans on vaccine supplies. Johnson said he believed one key error was a failure to appreciate how the disease could spread asymptomatically, while his chief scientific adviser, Sir Patrick Vallance, said lack of testing capacity and data meant the government lost control of tracking the virus’s spread. “I think in retrospect, there are probably many things that we wish that we’d known and many things that we wish we’d done differently at the time, because we were fighting a novel disease under very different circumstances than any previous government had ever imagined,” Johnson said. “Perhaps the single biggest false assumption that we made was about the potential for asymptomatic transmission, and that did govern a lot of policy in the early days. All that misunderstanding about the reality of asymptomatic transmission certainly led to real problems that [meant] we then really had to work very hard to make up ground.” Though evidence of asymptomatic transmission only became widespread public knowledge in March 2020, preliminary evidence was already being presented to the government from late January. In the minutes of the government’s Scientific advisory group for Emergencies (Sage) from 28 January, it says: “There is limited evidence of asymptomatic transmission, but early indications imply some is occurring.” It says Public Health England was investigating the prevalence of such transmission. A fortnight later, it says better testing of travellers would be needed to understand asymptomatic cases. Johnson refused to say he regretted the decision not to lock down the country earlier, both at the start of the first wave and the second , the latter of which he is said to have personally strongly opposed. “All I can say is we took all the decisions with the interests of the British people foremost in our hearts and in an effort to protect the public and to prevent death and suffering,” he said. “That was what we were trying to do at all stages.” But he again refused to put a date on a time for an inquiry, saying only that “doubtless there will be a moment to properly review, to learn lessons and make sure we learn them for future pandemics”. Labour said many of the errors had been made by Johnson and urged him again to order an inquiry. “The tragic reality is we’ve seen a litany of errors from Boris Johnson,” said the shadow health secretary, Jon Ashworth. “Public health should have been central to our response from the start, the failure to sufficiently financially support people to isolate has been a monstrous failure, the lack of protection for care homes was negligent, contact tracing should have been community led. And years of underfunding and cutbacks left our NHS vulnerable and exposed when the virus hit. Given future pandemic risk lessons must be learned – meaning a public inquiry is vital.” Vallance said having adequate testing in place at the beginning of the pandemic would have made a significant difference. “The one thing that I think would have been really important earlier on is to have much better data on what was happening. And that would have required testing to be up and ready immediately and it would have required the ability to get that information into a source and to be able to see it,” he said. “We simply didn’t have that at the beginning and it was very difficult to know the speed at which things were moving and therefore make decisions based on the real-time data, which we can do now, and that would’ve made a big difference.” Whitty said the UK had had “a bad outcome” but said similar results had been seen across many other countries. “What we want to try and do is to minimise mortality and learn lessons from the past,” he said. He said there had been “much less of an understanding about how widespread the virus was in Europe for exactly the same reason … because of the lack of testing in Europe as well as in the UK”. Whitty said the UK now knew that the virus had been imported from Spain, France and parts of Italy that were not seen as being particularly high risk. “At the time we didn’t have that information and that would have almost certainly have led to slightly different approaches to how we did things,” he said. He also repeated his warnings that the world was unlikely to eradicate Covid-19 even with mass vaccination. “We’ve only achieved eradication of one disease, which is smallpox, with a phenomenally effective vaccine over a very long period of time, literally hundreds of years,” he said. Prof Neil Ferguson, the Imperial College London epidemiologist who gave crucial advice to the government ahead of the first lockdown, said on Tuesday that an inquiry should start in the next few months. “Frankly we need an inquiry to properly go through both the advice at the time but also what was going on with the government at the time to address the issue of why didn’t we lock down a week earlier or two weeks earlier,” he said. “With an inquiry that lasts three years, the risk is that in three years time people’s concerns will have moved on and it’s less likely to affect real change.”