Visitors wearing protective masks to help curb the spread of the coronavirus stroll at Sensoji Temple in the Asakusa district in Tokyo, on Tuesday, November 30, 2021. The omicron variant kept a jittery world off-kilter as Japan further tightened travel restrictions, infections linked to the new version of the coronavirus popped up in more places and new evidence made clear the mutant strain was circulating weeks earlier than thought. (Photo by Koji Sasahara/AP Photo)
