Royal Caribbean International has joined the list of cruise lines that will mandate COVID-19 vaccines for crew members before sailings resume.

As first reported by RoyalCaribbeanBlog , the cruise company reportedly sent a notification to employees that coronavirus vaccines would be required for crew members if they wished to return to work.

The leaked documents revealed that Royal Caribbean did not know how or when the vaccine would be distributed, saying it would likely depend on “the country of residence, the timing of the next contract and whether the crew is already on board or traveling.”

In a statement released to TravelPulse, Royal Caribbean Corporate Reputation manager Jonathon Fishman spoke about the cruise line’ shifting focus when preparing to battle COVID-19.

“The health of our crew and guests remains our number one priority,” Fishman said. “At this point in our planning, based on science and the guidance of our experts, we are shifting from a strategy based primarily on protocols to one that is based on vaccines, supported by protocols.”

Royal Caribbean’s decision comes just weeks after Norwegian Cruise Line announced it would require that all crew members receive a COVID-19 vaccine treatment before the company begins sailing again.

Other cruise lines—such as Saga, American Queen Steamboat Co. and Victory Cruise Lines—have revealed they would require proof of COVID-19 vaccinations from all passengers and crew members administered at least 14 days before boarding a ship.