A surge in the number Covid-19 infections in Britain is leading to calls for a return of facemasks in crowded indoor spaces. The number of new coronavirus cases shot up by more than 30 per cent in the past week to reach three million, data released by the Office for National Statistics (ONS) on Friday showed. There was no equivalent increase in the number of hospital admissions linked to Covid-19. Variants of the Omicron strain,<a href="https://www.thenationalnews.com/world/uk-news/2021/11/29/what-is-the-omicron-covid-variant-everything-you-need-to-know/" target="_blank"> first detected in the UK last November,</a> are believed to be driving the increase. Dr Mary Ramsay, of the Health Security Agency, responded to the data by saying it is “sensible” for people to wear masks in places where they are cramped amongst others. The rule that made mask-wearing mandatory in indoor public spaces in England was<a href="https://www.thenationalnews.com/coronavirus/2022/01/27/uk-shoppers-and-commuters-asked-to-wear-masks-despite-law-change/" target="_blank"> dropped in January.</a> The devolved administrations followed suit. “Covid-19 has not gone away,” Dr Ramsay said. “It is also sensible to wear a face covering in crowded, enclosed spaces,” she said. Prof Christina Pagel of University College London said the government should improve ventilation in indoor spaces because this would be a longer-term solution to the spread of Covid. “It is so frustrating that we've wasted two years now in failing to improve our indoor air quality,” she tweeted. “Right now, masks will help ― I certainly wear one in crowded public spaces.” She stressed that the strategy to tackle rising infections is “not about temporary restrictions or ‘do nothing’ ― we need sustainable action to reduce transmission”. “Even if they won't stop waves entirely, they will reduce their size,” she said. Prof Pagel pointed to tweets she had put out in recent weeks predicting a possible new wave of cases, and said "this was not a surprise ― and next one won't be either". She said the current surge in infections may not be smaller than previous ones. This week French authorities <a href="https://www.thenationalnews.com/coronavirus/2022/06/28/france-asks-citizens-to-wear-masks-again-on-public-transport/" target="_blank">asked people to wear face coverings on public transport </a>amid increasing coronavirus case numbers. The latest jump in cases in the UK comes after an earlier increase of about 40 per cent last month, following the large street parties, concerts and festivities held to mark Queen Elizabeth II’s platinum jubilee celebrations. British officials said the latest wave of infections was probably caused by <a href="https://www.thenationalnews.com/coronavirus/2022/06/16/covid-19-pandemic-not-over-as-omicron-variants-threaten-new-waves/" target="_blank">Omicron subvariants BA.4. and BA.5. </a>Omicron has tended to cause a milder disease than previous variants Alpha or Delta, but scientists say its ability to evade the immune system means that people may be more susceptible to being reinfected, including after vaccination. Dr Stephen Griffin, associate professor of medicine at the University of Leeds, said: “The constant bombardment of waves we are seeing does cause clinical impact that is not to be underestimated." Despite widespread immunisation against Covid across the UK, the protection from vaccines is possibly fading. Britain’s Health Security Agency said they were seeing more outbreaks in care homes for older people and an increase in admissions to intensive care units of people over 65.