LONDON — As the still-mysterious Omicron variant reached American shores, the World Health Organization on Wednesday scolded wealthy countries that imposed travel bans and dismissed those that poured resources into vaccine booster campaigns when billions in poor countries had yet to receive their first shots.
The comments by W.H.O. officials reopened fraught questions of equity in how the world has handled the coronavirus pandemic since a stark divide over the availability of vaccines emerged between rich and poor countries earlier this year.
But amid fears of a new wave of Covid-19, that seemed unlikely to sway leaders in Europe, Asia, and the United States, which reported its first confirmed Omicron case, in California, on Wednesday. They are scrambling to shield their populations from the variant — about which much remains unknown — by topping up their protection and tightening restrictions on incoming travel.
Travelers reacted with confusion and dismay to news that the United States plans to toughen testing requirements and the screening of inbound passengers. That decision came after Japan, Israel, and Morocco barred foreign travelers and Australia delayed reopening its borders for two weeks.
revealed to the world — and Dr. Tedros warned that the number would rise.
The W.H.O. also voiced skepticism about ambitious booster plans that it claimed come at the expense of first-time vaccinations in less wealthy nations. Britain this week announced a massive new campaign to deliver booster shots to all adults by the end of January. Other European countries and the Biden administration are also pushing these shots as a first line of defense against the variant, buying time for scientists to unravel its genomic code.
Japan joined Israel and Morocco in barring all foreign travelers, and Australia delayed reopening its borders for two weeks. The C.D.C plans to increase testing and screening of international fliers to the U.S.