The US Centers for Disease Control and Prevention (CDC) said people should avoid travelling on cruise ships regardless of their vaccination status, as daily Covid-19 cases in the country climb to record highs due to the fast-spreading Omicron variant.
Photo: 123RF
The move delivers another blow to an industry that began returning to the seas in June after a months'-long suspension of voyages caused by the pandemic.
For the second day in a row, the United States had a record number of new cases based on the seven-day average, with more than 290,000 new infections reported each day, a Reuters tally showed.
The CDC raised its Covid-19 travel health notice level for cruise ships to four - its highest warning level - from three, citing reports of Covid-19 outbreaks on cruises.
The health agency has investigated or started an investigation into Covid-19 cases on more than 90 ships.
"Even fully vaccinated travellers may be at risk for getting and spreading Covid-19 variants," the CDC said on Thursday.
Shares in Carnival, Norwegian Cruise Line Holdings and Royal Caribbean Group reversed course after the news to fall between 1 percent and 2 percent.
"The decision by the CDC to raise the travel level for cruise is particularly perplexing considering that cases identified on cruise ships consistently make up a very slim minority of the total population onboard," the Cruise Lines International Association said.
The CDC said passengers already on cruise ships should get tested three-to-five days after their trip ends, and self-monitor for Covid-19 symptoms for 14 days.
The health agency had eased its warnings for cruises by a notch from the highest level in June after cases had eased.
The spread of Omicron also continued to impact air travel on Thursday. Total flight cancellations within, into, or out of the United States stood at almost 1140, with nearly 9000 flights delayed, data from flight-tracking website FlightAware.com showed.
Warning of 'viral blizzard'
US health experts have urged Americans to prepare for severe disruptions in coming weeks as the rising wave of Covid-19 cases led by the Omicron variant threatened hospitals, schools and other sectors impacting their daily lives.
The warning came amid record US Covid-19 cases, while federal officials issued more travel warnings and reportedly prepared to authorise booster shots for 12-to-15-year-olds next week.
At least 18 states and Puerto Rico have set pandemic records for new cases, according to the Reuters tally. Maryland, Ohio and Washington, DC, also saw record hospitalisations as overall US Covid-19 hospitalisations rose 27 percent.
A girl receives a self-testing kit at a screening centre in Los Angeles, as the pandemic continues to lead to a surge in cases across the US. Photo: AFP
The surge comes amid increased holiday travel, with New Year's celebrations still to come, and as schools grapple with students' return to classrooms following winter breaks.
"We are going to see the number of cases in this country rise so dramatically, we are going to have a hard time keeping everyday life operating," Dr Michael Osterholm, an infectious disease expert at the University of Minnesota, told MSNBC.
"The next month is going to be a viral blizzard," he said. "All of society is going to be pressured by this."
Dr Anthony Fauci, the nation's top infectious disease official, on Wednesday said cases will likely rise throughout January.
He and other US health officials have said early data show Omicron appears less severe but have continued to push vaccinations, masks and physical distancing. The CDC has also issued new guidelines shortening isolation and quarantine periods, which have been criticised by some disease experts.
The New York Times reported on Thursday that US health regulators planned to approve a third vaccine dose for 12-to-15-year-olds next week. Boosters are already approved for those 16 and older.
With testing shortages and breakthrough cases, experts warn the surge will still upend hospitals, emergency response services, schools and retailers, among others, in coming weeks.
"We have to be really careful about being too dismissive of Omicron," Dr Peter Hotez, an infectious disease expert at Baylor College of Medicine, told CNN.
Rising hospitalisations as healthcare workers are sidelined with their own Covid-19 infections is also concerning, as are fewer effective therapeutics, Hotez said. "We're in for a pretty serious time."
Already, 825,663 people have died in the United States from Covid-19 since early 2020, data showed, with the latest wave of hospitalisations driven by those not vaccinated.
President Joe Biden this month announced new plans to combat Omicron, including federal reinforcements for hospitals and more tests. But some experts have said it is too little, too late.
-Reuters