A cruise ship departing from Texas detected a handful of COVID-19 positive people on Wednesday, August 11, and most of them were crew members. 

The Carnival Vista, which was about to make a stop in Belize City, had to return to Galveston, Texas, where it sailed off after it found 26 of the crew members and a guest infected with COVID-19, ABC News reported.

All the infected individuals were breakthrough cases, as all were fully vaccinated against the virus. According to the Belize Tourism Board, none of the infected people suffered severe symptoms and were put in quarantine.

“With the stringent protocols, it is inevitable that COVID cases will be detected, but it is imperative that these situations are handled correctly to avoid further spread or unnecessary cancelations,” the board said. “According to our local protocols, passengers will not be allowed to disembark if the total number of positive cases exceeds 2% of the ship’s passengers.” 

The cruise ship had a crew of approximately 1,400 people on board and nearly 3,000 passengers. It was confirmed that 99.98% of the crew members had been vaccinated, and so were most of its guests, at 95%. 

Carnival Vista made a stop in the Caribbean port of Cozumel on Thursday, August 12, and some passengers had left the ship following their negative test results. The remaining guests are expected to disembark in Galveston on Saturday. 

“The team at Carnival noted that all positive cases have been isolated and contact tracing has ended with no additional positive cases found, and that the infected crew and passenger do not pose a threat to guests, crew or frontline workers in Belize,” according to The New York Post.

Carnival Vista is the first ship to resume operation this year after the COVID-19 pandemic started in the U.S., the outlet noted, which had sailed off on July 3.

The cruise ship had required all passengers to be vaccinated but still granted exceptions for children and those with medical complications. In the latest COVID-19 protocol update on August 4, Carnival had added a mask mandate in some indoor places and required all cruises to accept COVID-19 negative guests starting from August 14.

“We expect these requirements will be temporary and appreciate the cooperation of our guests,” said Christine Duffy, president of Carnival Cruise Line. “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.”

The Centers for Disease Control and Prevention (CDC) notified that it was investigating the situations with Carnival Vista.