The cascade of travel closures triggered a wave of resentment among Africans who believed that the continent was yet again bearing the brunt of panicked policies from Western countries, which had failed to deliver vaccines and the resources needed to administer them.

Richer countries, having already hoarded vaccines for much of 2021, were now penalizing parts of the world that they had starved of shots in the first place, scientists said.

“Told you so,” said Francois Venter, a researcher at University of the Witwatersrand in Johannesburg, referring to warnings from African researchers that delaying vaccinations there risked the emergence of new variants. “It feels like these rich countries have learned absolutely nothing in terms of support.”

The sense of outrage was most visceral in South Africa, where business leaders predicted a dire economic toll, especially on tourism. In the arrivals halls of Johannesburg’s O.R. Tambo International airport, Ronald Masiwa, a tour operator, watched with dread as the information board flipped to red, displaying cancellation notices. Three clients had already canceled trips overnight, and he feared that many more would follow.