The obligation to use face masks in public spaces as a public health measure and permissible limits on civil liberties

During the COVID-19 pandemic, authorities have imposed various social restrictions on a massive scale. This Viewpoint discusses current issues about the legality of restrictions and current knowledge about how to prevent the spread of Sars-Cov-2. Although vaccines are already available, other basic public health measures are needed to suppress the transmission of SARS-CoV-2 and reduce the COVID-19 related mortality: isolation, quarantine, and wearing of face masks. This Viewpoint shows that the emergency measures during a pandemic are important for protecting the public’s health, but they may only be legitimate if they are based in law, are in accordance with medical knowledge, and aim to limit the spread of infectious agents. We concentrate on a legal obligation to wear face masks as it became a most recognizable symbol of the pandemic. It was also one of the most criticized obligations and the subject of divergent views.