The UK’s Covid alert level has been downgraded from “critical” to “severe”, as cases and deaths continue to fall and the threat of the NHS being overwhelmed recedes. The move, which means transmission of coronavirus is considered to be “high or rising exponentially”, was recommended by the Joint Biosecurity Centre. The chief medical officers for all four UK nations and the medical director of NHS England agreed and directed for the alert level to be lowered from five, the highest level, to four. They said health services across the UK “remain under significant pressure” with “a high number of patients in hospital”. But they added: “Thanks to the efforts of the public we are now seeing numbers consistently declining, and the threat of the NHS and other health services being overwhelmed within 21 days has receded.” People should “be under no illusions”, the experts said. “Transmission rates, hospital pressures and deaths are still very high.” The chief medical officers said that despite the fast deployment of vaccines, it was “really important that we all – vaccinated or not – remain vigilant and continue to follow the guidelines”. They added: “We know how difficult the situation has been and remains to be for healthcare workers. We thank them for their immense effort, skill and professionalism throughout the pandemic.” There were 9,938 new coronavirus cases and 442 more deaths reported in the past 24 hours, according to the latest data released by the government on Wednesday. Another 353,009 people had received a vaccine dose, taking the total to nearly 19 million. Surge testing has been expanded to an area in the IG1 postcode in Redbridge, east London, to suppress the potential spread of the South Africa coronavirus variant. The Covid alert levels were devised last May to rank the threat from coronavirus as the UK began to ease the first set of lockdown restrictions. The level was raised from four to five at the start of January as England prepared to go into its third national lockdown. At the time, all four UK nations’ chief medical officers said cases were “rising almost everywhere, in much of the country driven by the new more transmissible variant”.