“Avoid cruise travel, regardless of vaccination status,” the CDC said in a travel caution posted on its website. “The COVID-19 Travel Health Notice level has been updated from Level 3 to Level 4, the highest level. This reflects increases in cases onboard cruise ships since identification of the Omicron variant.”
The Omicron variant, first detected in South Africa in November, is said to be more transmissible but causing mild cases and being far less deadly than the Delta variant that had spiked earlier this year.
On Wednesday, US presidential medical adviser Anthony Fauci said that Omicron cases were likely to peak in the United States by the end of January.
CDC data on Tuesday showed that Omicron accounted for 58.6% of all new infections in the United States in the week to December 25. The seven-day average for coronavirus cases was at 240,400 per day, some 60% higher than the previous week.
“Getting vaccinated is still the best way to protect yourself from severe disease, slow the spread of COVID-19, and reduce the number of new variants,” the CDC said. “People who are not fully vaccinated should follow additional recommendations before, during, and after travel.”
According to the CDC, more than 61% of the total US population is fully vaccinated, and over 32% of fully vaccinated adults have received a "booster" dose.