The latest travel rule changes are "a case of shutting the stable door after the horse has bolted," a scientist advising the government has said.

Several dozen cases of the new Omicron variant of the coronavirus have been identified in the United States, a number that is “likely to rise,” Dr. Rochelle P. Walensky, the director of the Centers for Disease Control and Prevention, said on Sunday on ABC’s “This Week.”

Two men in the southern Indian state of Karnataka have tested positive for the Omicron coronavirus variant after returning from overseas.

Germany's national and regional leaders have agreed to bar unvaccinated people from much of public life in a bid to fend off a fourth wave of Covid-19.

President Joe Biden’s administration will extend requirements for travelers to wear masks on airplanes, trains and buses and at airports and train stations through mid-March, sources briefed on the matter told Reuters, amid concerns about a new Covid-19 variant.