27 People Test Positive for COVID-19 on Carnival Cruise Ship Carrying Nearly 4,500
Twenty-six crew members and one passenger have tested positive for COVID-19 aboard a Carnival cruise ship that departed from Galveston, Texas.
The Carnival Vista ship was carrying 2,895 passengers and 1,441 crew members, the Belize Tourism Board announced in a statement on Wednesday ahead of the cruise's arrival.
All of the 27 people who contracted COVID-19 were vaccinated breakthrough cases that were either "asymptomatic or have very mild symptoms," Belize officials stated.
"The team at Carnival noted that all positive cases have been isolated and contact tracing has ended with no additional positive cases found," the statement continued.
COVID-19 infections that occur in people who have been fully vaccinated against the virus — are rare, but possible and expected, as the vaccines are not 100% effective in preventing infections. Still, vaccinated people who test positive will likely be asymptomatic or experience a far milder illness than if they were not vaccinated. The majority of deaths from COVID-19 — around 98 to 99% — are in unvaccinated people.
Of those on the ship, 96.5 percent of passengers were vaccinated and 99.98 percent of the crew was vaccinated.
Belize officials said all crew members who tested positive are in isolation — although it's unclear if the same is true of the single passenger. Carnival also completed contact tracing on Wednesday after testing over 400 people on Saturday, over 300 people on Tuesday and over 200 people on Wednesday.
Because the number of positive cases was under 2 percent, guests were able to disembark and "conduct shore excursions as per normal."
Since the outbreak, Belize officials said Carnival implemented additional safety protocols such as increased mask usage and closing social areas for the crew.
Additionally, regardless of vaccine status, travelers will be required to have a negative COVID test before continuing on to the next destination of the cruise (Cozumel, Mexico) on Saturday.
"The safety of guests, crew and frontline tourism workers is the highest priority for cruise lines and destinations. The ability to manage and control health-related matters, COVID-19 in particular, is fundamental to the operations of all involved," Belize officials wrote. "Cruise lines have been sailing globally throughout the pandemic, and in July, resumed sailing in the Western Caribbean and Belize."
A spokesperson for Carnival told PEOPLE in a statement that they are "managing a small number of positive COVID cases on Carnival Vista sailing out of Galveston."
"We have managed the situation utilizing stringent health protocols which included placing those who tested positive in isolation and close contacts in quarantine," a cruise line spokesperson said.
They also noted that anyone who departed on July 31 and August 7 was notified of the cases.
Cruise officials discovered the 27 positive cases during their process of "randomly test a large percentage of our crew on a rotating basis multiple days per week even though all are vaccinated." Belize health officials also randomly tested 68 guests before they disembarked on Wednesday.
"The health, safety and well-being of our guests, crew and the destinations we visit is our priority. All activities on the ship are taking place and our guests have been terrific at adapting to our new protocols," the spokesperson told PEOPLE. " Carnival is in daily contact with the CDC about the status of all our ships. Our onboard protocols exceed the CDC guidelines. The CDC's conditional sail order and our own protocols anticipate the potential for COVID on board, and our procedures are designed to manage and mitigate any situation."
The company is also implementing a new policy beginning on Saturday requiring all vaccinated guests to also show proof of a negative COVID test taken within 24 hours of departure — a rule that was already in place for unvaccinated guests.
Passengers on Carnival cruise ships are required to be vaccinated unless they have a medical or religious exemption or they are a child under 12 who is ineligible.
As information about the coronavirus pandemic rapidly changes, PEOPLE is committed to providing the most recent data in our coverage. Some of the information in this story may have changed after publication. For the latest on COVID-19, readers are encouraged to use online resources from the CDC, WHO and local public health departments. PEOPLE has partnered with GoFundMe to raise money for the COVID-19 Relief Fund, a GoFundMe.org fundraiser to support everything from frontline responders to families in need, as well as organizations helping communities. For more information or to donate, click here.