More than 137,000 new Covid cases have been reported for England and Wales on Sunday, official data reveals, as concerns grow about the spread to older adults. Figures have not been reported for Scotland or Northern Ireland due to the new year weekend, but in the past 24 hours 137,583 new Covid cases have been reported for England and Wales combined. The figures for England and Wales also show that there were another 73 deaths within 28 days of a positive test, while in England there were 13,151 patients in hospital, up from 12,615 the day before. On Saturday cases in England alone hit 162,572, a new record high for daily reported cases. However, figures tend to be lower on Sundays and early in the week as a result of fewer tests being taken over the weekend. Daily case numbers refer to cases by date reported, only cover infections picked up by testing and do not include reinfections – although the Guardian understands these may be included from the end of January – meaning the true number of infections will be higher still. Prof Sir David Spiegelhalter has said the UK’s daily Covid infections could be closer to 500,000 given normally less than half of infections are recorded as positive cases, while reinfections are not counted and testing is limited, meaning the proportion could now be even smaller. According to data from the Zoe Covid study, there were 205,235 new symptomatic cases of Covid alone in the UK on New Year’s Eve, based on PCR and lateral flow test data as of two days ago, with almost 2.4 million people predicted to currently have symptomatic Covid. According to official data for England, while cases began rising sooner among younger age groups, since around the middle of last month they have also been rising rapidly in those over the age of 60. Tim Colbourn, professor of global health systems, epidemiology and evaluation at the UCL Institute for Global Health, said that the peak of the Omicron wave might also be some weeks away. “Case numbers in London – which is ahead of the rest of the country in the Omicron wave – seem to be going up again after voluntary reduced mixing before Xmas had suggested a peak,” he told the Guardian, noting that still-incomplete cases by specimen date are the highest ever for London at 31,444 on 29 December. “Xmas and New Year’s mixing is likely to increase cases in London and the whole of the UK further over the coming days,” Colbourn added. Prof Graham Medley, a member of Sage, said data on cases is hard to interpret directly at the moment, given that testing supply is probably below demand. “More importantly, the delays in testing that are changing day to day make it harder to understand the dynamics,” he added. “But any rise in cases in older people is a concern.” Prof Andrew Hayward, co-director of the UCL Institute of Epidemiology and Health Care, agreed. “Omicron moving into the older population is a pivotal moment in the Omicron crisis. We only really expect hospitalisation rates to rise dramatically a couple of weeks after the infection has started to infect the older population, who are at most risk of severe disease,” he said. “We will likely start to see the impact of intergenerational mixing over Christmas on hospitalisation rates over the next week or two. Also, as the elderly were the first to get boosted they have had longest for immunity to wear off.” Prof Adam Finn, of the University of Bristol and a member of the Joint Committee on Vaccination and Immunisation, said questions remain about the proportion of older people who will become sick enough to require hospitalisation in the coming few weeks. “It’s now clear that a smaller proportion of people who get Omicron infection end up in hospital than was the case with earlier variants, although it remains unclear how much of this welcome trend is down to immunity from vaccines and previous infections and how much down to this new variant being a less aggressive virus,” he said. “Either way, although we are learning fast, the margins of uncertainty around this Omicron wave are still wide and people would be well advised to remain cautious and avoid infection as best they can for now as it still looks as though we are in for a very tough couple of months at least.”