RELATED: People Without a Booster Will Be Barred From This, as of Feb. 1.ae0fcc31ae342fd3a1346ebb1f342fcb Luxury cruise lines Silversea and Azamara have announced that they will require all passengers to have received COVID-19 booster shots before boarding and embarking, as of March 1, Travel + Leisure reports. The policy move makes them the first major cruise lines in the world to establish a mandate for the supplemental doses. Currently, both companies require that all passengers have completed their full initial vaccine regimen—which includes two shots of mRNA-style vaccines such as Pfizer or Moderna or a single shot of Johnson & Johnson vaccine—a full two weeks before their voyage begins and to take a rapid antigen test before boarding. Passengers eligible to receive their boosters will have to show proof they’ve received one on both Azamara and Silversea cruises beginning in March. “At Silversea, our top priority has always been to safeguard the health and safety of our guests, crew, and the communities we visit,” the company wrote in a statement. “Silversea will continue to work closely with relevant governing bodies and health authorities to evolve its health and safety procedures, as new health recommendations are issued and as the fluid situation advances.”

RELATED: For more up-to-date information, sign up for our daily newsletter. While the two companies are leading the industry by enacting booster mandates, most cruise lines currently require all or the vast majority of passengers to be fully vaccinated before setting sail, CNN reports. In addition, many operators also require that passengers take a COVID test before departure regardless of vaccination status and enforce a mask mandate in all indoor public areas onboard. The policies were enacted as part of the CDC’s Conditional Sailing Order that allowed the industry to resume cruises after the pandemic kept them scuttled for more than a year. However, the CDC has currently still placed cruise travel in its top “Level 4: Very High” COVID-19 risk designation. The health agency advises against cruises at all costs, regardless of vaccination status, warning that “the virus that causes COVID-19 spreads easily between people in close quarters onboard ships, and the chance of getting COVID-19 on cruise ships is very high, even if you are fully vaccinated and have received a COVID-19 vaccine booster dose.” Despite the existing precautions, the CDC reported on Jan. 11 that COVID-19 cases on cruise ships sailing in American waters jumped from a total of 162 in the first two weeks of December to 5,013 between Dec. 15 and 29. In late December and early January, more than 20 cruises operated by lines including Norwegian and Royal Caribbean were canceled or postponed, The Washington Post reported on Jan. 13. Some that have set sail have been turned away from visiting ports or stuck moored with passengers on board, such as one New Year’s cruise operated by Carnival in Portugal that was cut short after 52 crew members tested positive for the virus mid-voyage. “We all want this to end. We’re going home,” one disembarking passenger told Reuters. RELATED: Unvaccinated People Will Be Fired From Here by Jan. 31.