As of 5 September, the lines will also allow unvaccinated passengers to sail with proof of a negative self-administered test. Guests five years old and younger have no vaccine or testing requirements.

However, on sailings of 10-plus nights, guests – vaccinated or unvaccinated – must provide a negative test within three days of their sailing date.

Due to local regulations, sailings to or from Australia, Bermuda, Canada, Singapore and Israel still require guests to be vaccinated.

"A new world is waiting and I’m thrilled to now more closely align our operations with the rest of the travel industry and open up opportunities for everyone to explore, once again," said Lisa Lutoff-Perlo, president and chief executive of Celebrity Cruises.

"Travel is making its grand comeback and we’re looking forward to the continued momentum from consumers around the world."