The governments of Greece, Italy, and Spain have reimposed outdoor mask mandates and introduced some new COVID-19 rules ahead of Christmas, citing the spread of the Omicron variant. Greece announced new restrictions on Thursday that include requiring people to wear masks for all outdoor and public areas. Meanwhile, double-masking or more protective filtering facepiece (FFP2) masks will be required for public transport and supermarkets. “Due to the large amount of Christmas activity and crowded conditions that it creates, the mandatory use of masks is fully justified,” Greek Health Minister Thanos Plevris said. The restrictions, to take effect on Friday and remain until at least Jan. 3, also ban all public events to celebrate Christmas and New Year. Greece will also strongly recommend incoming travelers to have follow-up COVID-19 testing—rapid testing or PCR—on the second and fourth day after their arrival, in addition to the already-mandated negative COVID-19 test to enter the country. …