The shares of Royal Caribbean Cruises ( RCL-US ), Norwegian Cruise Lines ( NCLH-US ) and Carnival ( CCL-US ) fell in response.

The highly contagious Omicron novel coronavirus has swept across the United States, and confirmed cases on cruise ships have surged. The Centers for Disease Control and Prevention (CDC) said on Thursday (30th) that regardless of the vaccination situation, the public is advised not to take cruises.

As CDC is investigating and observing dozens of ships that have outbreaks of new crown cases, CDC has also raised its travel warnings for cruise ships to the highest level.

Cruise ships operating in U.S. waters reported about 5,000 cases of COVID-19 to the CDC from December 15 to 29, a significant increase from only 162 cases reported in the first two weeks of the month.

The CDC said: "It is especially important that passengers at high risk of severe cases of new coronary disease should avoid cruises, including river ships and international cruises, regardless of their vaccination status."

This CDC proposal is undoubtedly another blow to the cruise industry, which was hit hard in the first year of the outbreak. The shares of Royal Caribbean Cruises ( RCL-US ), Norwegian Cruise Lines ( NCLH-US ) and Carnival ( CCL-US ) fell in response.

CDC warns that due to the close distance between people on cruise ships, it is easy to spread the virus. Even if vaccinated or even boosted, there is still a high chance of infection.

CDC recommends that cruise passengers should be vaccinated before departure, and if they meet the conditions, they must be vaccinated. They should wear masks in public spaces after boarding. Passengers who are not fully vaccinated should be quarantined for five days after the trip.

The CDC also stated that regardless of the vaccination status or symptoms, cruise passengers should be tested 1 to 3 days before departure and 3 to 5 days after travel. However, the home testing kits for the new coronavirus on the shelves of many pharmacies across the United States have been sold out, and there are long queues for testing in clinics.

Brian Salerno, senior vice president of maritime policy for the International Cruise Line Association, said the association’s decision to CDC was frustrating.

He argued that the handling policy of cruise ships is highly effective, and the level of cases on cruise ships is significantly lower than that on land.

The association spokesperson Anne Madison said that the number of new crown cases found on cruise ships accounted for only slightly more than half of the total number of cruise ships, and most of them were asymptomatic or mild, which would hardly burden medical resources on board or ashore.

According to data compiled by Johns Hopkins University, as of Wednesday, the average number of new diagnoses in a single day in the United States in 7 days exceeded 300,000, an increase of 82% from last week.