The UK could find itself back in a Covid-19 crisis surprisingly quickly, England’s chief medical officer has said. Chris Whitty urged the public to proceed with caution when <a href="https://www.thenationalnews.com/world/uk-news/2021/07/12/englands-unlocking-plans-will-proceed-on-july-19-despite-threat-of-virus-variants/" target="_blank">England lifts nearly all Covid restrictions on Monday, the long-awaited Freedom Day</a>. The spread of the Delta variant has sent infections soaring to their highest level in months, but deaths are still at relatively low levels thanks to a vaccination programme that has given at least partial protection to 88 per cent of adults. Mr Whitty said the country was in better shape as a result of the vaccines but warned that “we are not by any means out of the woods yet”. “It doesn’t take many doublings until we’re in actually quite scary numbers again,” he said at an event hosted by London’s Science Museum on Thursday. “I don’t think we should underestimate the fact that we could get into trouble again surprisingly fast.” Mr Whitty said he expected most people to maintain precautions and described anti-lockdown hardliners as a “very, very small minority”. He said the key on July 19 was to “take things incredibly slowly” when mask requirements and limits on social gatherings are abolished and the government lifts its advice to work from home where possible. “People have been incredibly good at saying, I may be a relatively low risk but people around me are at high risk and I’m going to modify my behaviours,” Mr Whitty said. The end of mandatory mask wearing is generating controversy, and <a href="https://www.thenationalnews.com/world/uk-news/2021/07/14/face-masks-to-remain-compulsory-on-london-tube-trains-and-buses/" target="_blank">some regions and businesses will continue to push for the use of face coverings</a>. The government says it expects and recommends that people will continue to wear masks in crowded places, such as busy trains. UK Prime Minister Boris Johnson has frequently described England’s path out of restrictions as irreversible. But ministers toned down that rhetoric in recent days and suggested that social curbs could return if the virus situation deteriorates. “Of course if we get into a situation where it’s unacceptable and we do need to put back further restrictions, then that of course is something the government will look at,” government minister Lucy Frazer told Sky News on Friday. With thousands being infected every day, many more are being told to isolate by the contact-tracing app run by the National Health Service. The latest figures showed that in the space of a week 520,000 people were pinged by the app and told to isolate. Fully vaccinated people are scheduled to become exempt from the isolation requirement, but not until August 16. Frustration over the app has led to reports of many people deleting the software to avoid being told to quarantine.