Omicron Could Knock a Fragile Economic Recovery Off Track

The latest zigzag in the pandemic has already curtailed travel, but its broader impact on growth and inflation isn’t likely to be known for several weeks.

LONDON — This week, Marisha Wallace finally had to admit that her planned five-day ski holiday in Switzerland in mid-December was not salvageable: The Swiss government’s sudden decision to impose a 10-day quarantine on some international travelers meant she wouldn’t be able to leave her hotel or return home to London on her scheduled flight.

“It’s the way of the world right now,” said Ms. Wallace, an actress and a singer. “You can’t plan anymore.”

That provisional state, amplified across the world, has left the still-fragile economy in a state of suspense as spiking coronavirus infections and the new variant Omicron have popped up around the globe.