NHS England's National Medical Director and the UK's four Chief Medical Officers have lowered the UK's Covid alert level to 4. Previously, the level was set at 5 - the highest possible - which represents levels of coronavirus presenting a "material risk of healthcare services being overwhelmed". The decision to move the UK down a level has been taken after latest figures on infections and hospitalisations, as well as advice from the Joint Biosecurity Centre. However, with level 4 representing "a high or rising level of transmission", experts have warned the general public not to get complacent about the virus. Officials have warned that hospitals in the UK “remain under significant pressure with a high number of patients in hospital”. A total of 16,800 people currently receiving treatment in hospital for the virus. 'Remain vigilant' In a joint statement, the Chief Medical Officers said: “We should be under no illusions” about the still-present risks of coronavirus. “In time, the vaccine will have a major impact and we encourage everyone to get vaccinated when they receive the offer. However for the time being it is really important that we all - vaccinated or not - remain vigilant and continue to follow the guidelines,” said the statement. “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", it added.Alert level must reach 2 or 1 to completely lift restrictions Revealing a roadmap out of lockdown on 22 February, Prime Minister Boris Johnson expressed hopes that all restrictions on social contact could be lifted by June. To be able to do this, the coronavirus alert level would have to sit either at level 2 (the number of cases and transmission are low), or level 1 (Covid-19 is no longer present in the UK) to allow for minimal or no social distancing. The PM has indicated the government will be guided by "data not dates" on the easing of lockdown measures.