A US Cruise Ship Had a COVID Outbreak Even Though Full Vaccination Was Required—Here's What You Should Know

In December 2021, a Norwegian Cruise Line ship that disembarked from New Orleans reported 17 cases of COVID-19 among passengers and crew members. The positive cases include one probable case of the Omicron variant, which was detected in a crew member, according to a news release from the Louisiana Department of Health.

The Norwegian Breakaway left New Orleans on November 28 and stopped in Belize, Honduras, and Mexico on its voyage before returning to New Orleans on December 5, the health agency said. There were more than 3,200 people on board.

Initially, when the Louisiana Department of Health first released the infection news on Saturday, December 4, there were 10 people on the cruise who had tested positive for COVID. The following day—the day passengers started to leave the ship—the department announced that there were seven more confirmed cases.

The passengers and staffers with COVID-19 have been isolated, according to the health department. And before getting off in New Orleans, everyone on the ship had to be tested for COVID-19. "Those who test positive for COVID-19 will either (1) travel by personal vehicle directly to their personal residence or (2) self-isolate according to current CDC guidelines in accommodations provided by Norwegian Cruise Line," the news release said. Everyone was also provided with "post-exposure and quarantine public health guidance by the [Centers for Disease Control and Prevention] CDC," the Louisiana Department of Health said.

Norwegian Cruise Line has a strict COVID-19 vaccination policy, requiring that everyone on board be fully vaccinated against the virus. "All guests and crew are required to be 100% fully vaccinated so you can safely do what you've always wanted to do on a cruise — EVERYTHING," the company's website reads. "Let's get back to living life to the fullest, together. Sail Safe. Feel Free."

The cruise line also requires passengers to take a COVID-19 test and receive a negative result before boarding. Under normal circumstances, Norwegian Cruise Line offers testing for people leaving the ship whose home country requires a negative test.

[Editor's Note: Norwegian updated their vaccination policy stating, "Effective for sailings 10/4/22 and beyond, all guests regardless of vaccination status are able to sail and with no testing requirements. This does not supersede country-specific requirements."]

Because of its vaccination and COVID mitigation policies, the cruise line advertises that there is "no social distancing required" on its ships, there are no capacity restrictions, and people can dine on any of the company's ships mask-free. (Although, the CDC does say that everyone who goes on a cruise covers their nose and mouth in shared spaces.)

The CDC currently recommends that people who are not fully vaccinated against COVID-19 avoid traveling on cruise ships, noting that the odds of getting COVID-19 on a cruise ship is "high." However, many cruise ships now list full vaccination as a requirement for sailing.

Experts say it's not shocking that breakthrough COVID cases would happen on a cruise—even if everyone was fully vaccinated. "Obviously, there are breakthrough infections. That is always a risk," Reynold Panettieri, MD, vice chancellor for translational medicine and science at Rutgers University in New Jersey, tells Health.

Thomas Russo, MD, professor and chief of infectious disease at the University at Buffalo in New York, agrees. "Even if everyone is fully vaccinated, the vaccines are not perfect," he tells Health, noting that he personally now considers "fully vaccinated" to mean having three doses of an mRNA COVID-19 vaccine and two doses of the Johnson & Johnson vaccine. (Cruise ships, however, only require two doses of the mRNA vaccine and one of the Johnson & Johnson vaccine.)

Testing before boarding is also not a perfect science, Dr. Russo says. "There could be people on the boat who were infected and were asymptomatic but not infectious enough to be picked up on a test at boarding," he says. "You could test negative when you get on the boat and subsequently develop an infection."

Dr. Panettieri says it's important for people to consider their own personal risk-benefit analysis before getting on a cruise ship these days. "If you've had a booster, the likelihood of you having a severe COVID-19 infection if you get infected goes down," he says. "In the case of the Omicron variant, cases have mostly been mild so far but… we just don't know yet."

If you have an underlying health condition that puts you at an elevated risk of severe COVID-19, Dr. Panettieri suggests at least being aware that you could still get the virus on a fully vaccinated cruise. "You should probably pass on cruise ships at this time," Dr. Russo says. "Even though the odds of you getting infected when you're fully vaccinated on a fully vaccinated cruise are small-ish they're not zero." (The CDC also recommends that those with increased risk of severe illness, even if they are fully vaccinated, avoid cruise ships for the time being.)

Even if you're not concerned about how COVID-19 will impact your health, Dr. Russo points out that you may end up needing to quarantine if someone on the ship tests positive for the virus. "The health risk may be small, but the concern about ending up in quarantine or not being able to get home in time because you test positive could be problematic to you," he says.