Moving to step two of the government’s roadmap out of lockdown next week is “highly unlikely” to overwhelm the NHS – but further easing in the summer could unleash a third wave as deadly as that seen in winter, Sage scientists warn. Outbreak modellers have advised the government that the next step in reopening England, from 12 April, could cause infections to start rising again but not to a degree that is expected to put NHS care at risk. In papers released by Sage on Monday, the outbreak modelling subgroup said there was “considerable uncertainty” around the level of control that could be achieved at each step of the roadmap, but that moving to step two next week was “highly unlikely to put unsustainable pressure on the NHS”. After step one allowed schools to reopen, step two permits all retail to resume, along with the reopening of pubs, cafes and restaurants for outdoor eating and drinking only. Other venues, such as hairdressers and nail salons, libraries and indoor gyms and pools, are also due to reopen. Modelling teams on Sage made different assumptions about vaccine uptake and the effectiveness of the inoculations to prevent transmission and protect people from serious illness and death. Taken together, the experts warn that while step two next week may not cause serious problems. They say “it is highly likely that there will be a further resurgence in hospitalisations and deaths after the later steps of the roadmap”. In most of the scenarios modelled, the peak of the potential third wave is smaller than that seen in January this year, when more than half of the UK’s Covid deaths occurred. But work by the London School of Hygiene and Tropical Medicine found that with pessimistic but realistic assumptions about the effectiveness of vaccines, a third wave could peak at the end of July or early August with hospitalisations on the same scale as January. The model assumes that two shots of the AstraZeneca vaccine reduces the risk of infection by only 31% and the risk of symptomatic infection by 85%. Step three of the lockdown-easing roadmap aims to restart indoor hospitality and foreign holidays as early as 17 May, with step four removing all restrictions no sooner than 21 June. According to the modellers, some measures will still be needed thereafter, though. “Maintaining baseline measures to reduce transmission once restrictions are lifted is almost certain to save many lives and minimise the threat to hospital capacity,” they write. Since infections topped 60,000 per day in January, new cases in England have fallen about 95% to levels not seen since mid-September. Reported Covid deaths have fallen as low as 10 a day. The vast majority of the reduction comes from lockdown, though the impact of the vaccination programme has started to be felt, particularly in preventing deaths among the elderly and most vulnerable. Ministers must strike a delicate balance if they are not to squander the hard-earned gains of both lockdown and vaccination, and risk the political embarrassment of going back into lockdown in the months ahead. That means allowing aspects of normal life to return while keeping a watchful eye on cases numbers, hospital pressure, and the ever-present risk from new variants of the virus. “Going to step two seems OK to me, but we must not take the brakes off in a way that allows case numbers to soar upwards,” said Prof Peter Openshaw, a member of the government’s New and Emerging Respiratory Virus Threats Advisory Group (Nervtag). “It’s a concern that there are still thousands of people in the UK who are infected. It is ready to take off again if we start doing things that really do encourage transmission.” Many of the changes that come with step two involve outdoor activities, though restrictions on the numbers of people who can meet still apply. With the go-ahead from ministers, all retail in England can reopen, as can zoos and theme parks, and pubs, cafes and restaurants with outside seating. Unless people are crammed together, the risk of spreading the virus outside is far lower than indoors. But other venues, such as hairdressers and nail salons, libraries and museums, and indoor gyms and pools, are also included on the list, and may contribute to rises in infection. Outbreak modellers advising the government expect infections, hospitalisations and deaths to rise as England unlocks, but the size and timing of the resurgence is highly uncertain. Ministers are relying heavily on vaccination and tests to avert a brutal third wave, but some scientists argue that far more can be done. Venues and workplaces could be made more Covid-safe, and greater efforts made to help more people work from home, for example. Easier access to tests will help, but it is not enough on its own. The Corsair study published last week found that fewer than a quarter of people in the UK with Covid symptoms request a test. That does not bode well for the government’s latest offer for everyone in England to have twice-weekly lateral flow tests, said Prof Stephen Reicher, a member of the Sage’s behavioural science subgroup. “One of the main reasons people don’t test is they cannot afford to find out they are positive. What’s the point of increasing the number of tests available without addressing that question?” Reicher said people who tested positive needed full support so they did not delay in getting a test, and those who were infected could self-isolate without having to worry about their finances or anything else that puts them off. The traffic light system being drawn up ahead of the holiday season is expected to establish green, red and amber flags depending on the state of a country’s epidemic. People who arrive in England could then face either no restrictions, quarantine at home, or formal quarantine in a hotel. The intention is to keep an influx of infections – and particularly vaccine-resistant variants – at bay. But Reicher calls the traffic light system “bizarre” because tourist hotspots bring people together from all over the world. “We know there are all sorts of variants in all sorts of countries. If you go to a tourist destination, there will be tourists there, so what is the relevance of the local infection rate in the country?” he said. As England opens up, it will be even more crucial for people to engage with the test and trace system and feel able to self-isolate if they test positive, Reicher added. “My concern is there’s all this talk about the roadmap being irreversible, that we won’t go back into lockdown, but unless you put the measures in place, it’s just talk.” Prof Openshaw said it was crucial for test and trace to work more effectively as England came out of lockdown. “It is so vital that it works, but lots of people are opting out because of the practical problems they encounter,” he said. “In some countries really effective test and trace systems have been able to knock coronavirus on the head, practically, but for some reason we just don’t seem to be able to get that together.”