In this Tuesday, June 22, 2021 file photo, a restaurant employee, right, checks a visitor's COVID-19 vaccination QR code at the entrance of a restaurant in Moscow, Russia. Faced with worrying surges of coronavirus infections driven by the more transmissible delta variant, European nations have been scrambling to ramp up vaccination drives, using a mixture of stick-and-carrot measures to persuade the reluctant to get their shots. (Photo by Pavel Golovkin/AP Photo/File)
