Carnival Cruise Line (CCL) has confirmed that a “small number” of passengers onboard a fully vaccinated cruise have tested positive for COVID-19.

The COVID cases were reported Wednesday onboard the Carnival Vista cruise ship that departed out of Galveston, Texas, KTRK, an ABC affiliate out of Houston, Texas, reported.

"Our pre-established protocols of vaccinated guests and crew, testing, enhanced medical capabilities and contact tracing anticipated the potential for positive cases, and they are designed to adapt to various scenarios," Carnival said in a statement obtained by KTRK. "We have identified and tested close contacts and anyone who tested positive is in isolation."

The infections come with an update in COVID-19 cruise policies for passengers, which now require passengers to wear masks on board and to have a pre-cruise COVID test regardless of vaccination status.

A Carnival Cruise spokesperson told KPRC, an NBC affiliate out of Houston, about the new policies and confirmed COVID cases onboard the Vista ship.

“The decision to implement the mask policy was made in an abundance of caution, given our focus on the health and safety of our guests and crew. The voyage will continue as planned and we are dedicated to continuing to provide our guests with a fun and safe vacation.”

Carnival said it will continue to operate its fully vaccinated cruises, as defined by the CDC, with its fully vaccinated crewmembers and by asking its guest to wear masks in certain indoor areas of its cruise ships.

According to the cruise line’s website, masks must be worn "in elevators and in designated indoor entertainment areas, all retail shops, and in the casino, except when eating or drinking.”

The new face mask policy and pre-cruise COVID test requirement for all vaccinated passengers go into effect Saturday and will run through Oct. 31 at the earliest.

Vaccinated passengers will need to show proof of a negative COVID-19 PCR or antigen test that has been taken within three days of the cruise embarkation in order to board the ship.

“These new requirements are being implemented to protect our guests and crew while on board, and to continue to provide confidence to our homeports and destinations that we are doing our part to support their efforts to protect public health and safety,” Christine Duffy, president of Carnival Cruise Line, said in a statement.

“We expect these requirements will be temporary and appreciate the cooperation of our guests. Our first month of guest operations has been met with tremendous enthusiasm and very positive guest feedback, and we are committed to continue our restart with both fun and safety in mind.”

Unvaccinated passengers will continue to be required to have a pre-cruise PCR COVID-19 test, testing prior to boarding, and testing within 24 hours of debarkation on cruises of five days or longer. Unvaccinated guests who are departing from Florida or Texas must show proof of travel insurance.

Carnival Cruise Line boat
A Carnival Cruise Line ship is pictured here. AFP/Mark RALSTON