Cossacks wear protective face masks including SilverMask reusable face masks as they patrol the streets in Kaliningrad, Russia April 1, 2020. Scientists from the Immanuel Kant Baltic Federal University designed reusable face masks with multilayer structure which includes layers with the deposition of silver ions that they say have antibacterial and antiviral properties and give better protection against the coronavirus disease (COVID-19). Picture taken April 1, 2020. REUTERS/Vitaly Nevar