The World Health Organisation said on Saturday it was "very worried" Europe's <a href="https://www.thenationalnews.com/tags/covid/" target="_blank">Covid</a> surge could lead to 500,000 more deaths if immediate action is not taken, including the widespread resumption of mask-wearing. <a href="https://www.thenationalnews.com/tags/world-health-organisation/" target="_blank">WHO </a>regional director Dr Hans Kluge told the BBC that this would immediately help, unsurprising given a study released on Thursday found <a href="https://www.thenationalnews.com/health/2021/11/18/global-study-finds-masks-are-best-way-to-protect-against-covid-19/" target="_blank">wearing masks was the single most important infection prevention measure</a>. Dr Kluge said factors including winter, patchy vaccine coverage and the potency of the Delta variant were propelling the wave. He urged an increase in vaccine uptake, in conjunction with basic health protocols and <a href="https://www.thenationalnews.com/world/2021/11/05/pfizer-trials-show-its-antiviral-pill-cuts-risk-of-severe-covid-19-by-89/" target="_blank">new medical treatments such as Pfizer's Paxlovid</a>. Covid-19 has become once again the number one cause of death in Europe, but "we know what needs to be done" to combat the virus, he said. He stopped short of calling for the imposition of mandatory vaccinations, which have caused such uproar in Austria. However, he didn't rule the measure out as a last resort. While Austria has gone farthest to date, countries across Europe are ratcheting up restrictions again. Slovakia is banning people who haven’t been vaccinated from all non-essential stores and shopping malls. They also will not be allowed to attend any public event or gathering and will be required to test twice a week to go to work. “A merry Christmas does not mean a Christmas without Covid-19,” said Prime Minister Eduard Heger. “For that to happen, Slovakia would need to have a completely different vaccination rate.” He called the measures “a lockdown for the unvaccinated.” It is not only nations in central and eastern Europe that are suffering anew. Wealthy nations in the West are also being hit hard and imposing restrictions on their populations once again. “It is really, absolutely, time to take action,” German Chancellor Angela Merkel said. With a vaccination rate of 67.5 per cent, her nation is now considering mandatory vaccinations for many health professionals. “All of Germany is one big outbreak,” Lothar Wieler, head of Germany’s disease control agency, told reporters on Friday. “This is a nationwide state of emergency. We need to pull the emergency brake.” Greece, too, is focusing on the unvaccinated. Prime Minister Kyriakos Mitsotakis announced a battery of new restrictions late on Thursday, keeping people who have not been inoculated out of venues including bars, restaurants, cinemas, theatres, museums and gyms, even if they have tested negative. “It is an immediate act of protection and, of course, an indirect encouragement to be vaccinated,” Mr Mitsotakis said. Meanwhile the UK remains a complete outlier in Europe given its steadfast refusal to contemplate any form of Covid mitigation - except <a href="https://www.thenationalnews.com/coronavirus/2021/11/09/uk-health-secretary-javid-nhs-workers-will-have-to-be-vaccinated/" target="_blank">mandatory vaccines for healthcare workers</a>. On Friday it recorded 44,242 new infections. The last time its daily infections dipped blow the 30,000 mark was on September 19 when it recorded 29,612 new cases.