Carnival Corporation has confirmed its cruise brands will opt into new US Centers for Disease Control and Prevention (CDC) Covid protocols when operating in the US.

From 1 March, masks will be recommended but not mandatory onboard Carnival Cruise Line, Holland America Line, Seabourn and Princess Cruises voyages, although they may be needed for certain venues and events.

Carnival Cruise Line said it will continue to meet the standard of vaccinated cruises, but children under five would not be included in any vaccinated guest calculation and will not be required to receive an exemption to sail. The brand said it would also allow “additional flexibility” in pre-cruise testing requirements.

President Christine Duffy said: “The public health situation has continued to improve, providing confidence about these changes. Our protocols will evolve as we continue to remain dedicated to protecting the public health of our guests, crew and the communities we visit.”

Princess president John Padgett added: “Princess has proven cruise vacations are safe and healthy for our guests and teams. Going forward, Princess is prepared to adjust operating protocols to ensure our guests have amazing vacations while always protecting the safety of our guests, team members and destinations.

“We appreciate the ongoing collaboration among multiple government agencies as well as the support of Alaska officials and other delegations.”