Fifty-five people have tested positive for Covid-19 aboard a Royal Caribbean International cruise ship that set sail Saturday from the southeastern US state of Florida, the company said.
The infections on the "Odyssey of the Seas" involved passengers and crew members, even though 95 percent of the people on board were vaccinated against the coronavirus, Royal Caribbean said late Wednesday.
The Odyssey is carrying 3,587 passengers and 1,599 crew members, according to USA Today newspaper.
The shipping company said all 55 of those infected have been vaccinated against the coronavirus and are asymptomatic or have mild symptoms.
Their close contacts have been quarantined for 24 hours before undergoing a Covid test.
This is the second outbreak on a Royal Caribbean cruise ship in less than a week.
Last Saturday, the "Symphony of the Seas" returned to the port of Miami with 48 Covid-19 patients on board after a seven-day voyage in the Caribbean.
The industry resumed operations in June with strong security measures in place to guard against possible contagion.
Royal Caribbean requires, for example, that its passengers over the age of 12 and its employees be fully vaccinated.
But the highly contagious Omicron variant of the coronavirus poses a new challenge for the industry.