Germany’s carnival season, a series of festivals among German Catholics, began Thursday but under strict COVID-19 restrictions, because of a surge in new infections in the nation.

Costumed revelers in the western city of Cologne had to line up Thursday to show proof of their COVID-19 vaccinations before they could start the outdoor celebrations. Last year’s festivals were canceled altogether because of the coronavirus pandemic. 

The carnivals are being held despite the fact Germany is undergoing a fourth wave of COVID-19 infections, setting a record Wednesday for the number of daily infections.

And while the vaccine requirement was strictly enforced, the streets of Cologne were filled with people, side by side, without masks.

Thursday’s celebrations began with a somewhat ominous sign – designated so-called prince for the Cologne carnival, Sven Oleff, had tested positive for COVID-19 the previous day, a breakthrough case since he is fully vaccinated. The festival committee said he showed no symptoms and was feeling well.

The German celebrations – which Germans refer to as the “fifth season” – is a series of festivals celebrated originally by Catholics, primarily in Germany’s Rhineland region. They feature music, food and alcoholic beverages, and they run until Ash Wednesday in February – or the beginning of the Lenten season of fasting and reflection.