Princess Cruise Ship Docks in San Francisco With 12 COVID-Positive Passengers

A cruise ship from the Princess Cruise line docked in San Francisco on Thursday after random COVID testing of a quarter of the passengers revealed 12 positives on board.

The 10-day cruise to Mexico is one of the nearly 100 cruise ships under investigation by the Centers for Disease Control and Prevention because of COVID cases as of Thursday.

The 12 passengers, all vaccinated, are asymptomatic or have mild symptoms, according to a statement from the Port of San Francisco. A Princess Cruises spokesperson told The Associated Press the vaccination rate on the ship was "approaching 100 percent."

The Omicron variant has caused concern in the world of cruise ships, as the variant has proven to be more transmissible among those who are vaccinated than past variants.

Last week, the CDC recommended that all Americans should avoid cruise ships until Omicron and COVID at large subsides, prompting responses from several cruise lines highlighting the safety standards the industry is being held to.

Of the 22 cruises that have docked in San Francisco with COVID-positive passengers or crew, none of the cases have required hospitalization, and the port said all the ships have complied with CDC and San Francisco public health guidelines.

San Francisco, Princess Cruise Ships, COVID
People stand on a pier outside the Ruby Princess cruise ship and wait to be picked up in San Francisco on Thursday. The U.S. Centers for Disease Control and Prevention is investigating a cruise ship that docked in San Francisco on Thursday after a dozen vaccinated passengers tested positive for coronavirus. Eric Risberg/Associated Press

Cruise ships are required to notify the CDC of suspected or confirmed positive cases on board, and any vessel with 0.10 percent of passenger cases meet the criteria for investigation.

Cruise ships returned to San Francisco in October after a 19-month hiatus. The pause was sparked in March 2020 when the Grand Princess carried people infected with the coronavirus, sending thousands of passengers to quarantine in their cabins as the ship idled off the California coast. The ill-fated cruise captured the world's attention and made the coronavirus real to millions in the United States.

When business resumed, most cruise lines required adult passengers to show proof of vaccination against COVID-19.

Due to the surge, San Francisco is also asking cruise ships to test passengers who have not received their second doses or booster shots before letting them come ashore.

"This requirement is stricter than federal and state guidelines and is intended to protect the people of San Francisco," port officials said.

The passengers who tested positive will either go home or be taken to hotels for quarantine, spokeswoman Negin Kamali said.

Another Ruby Princess cruise ship is set to depart from San Francisco Thursday afternoon for another 10-day cruise to Mexico, she said.

The Associated Press contributed to this report.