Aurora Expeditions will now require guests, crew and expedition team members to be fully vaccinated against Covid-19 on all voyages.
The move comes as the line unveils an updated health and safety programme in preparation for the resumption of its expedition cruising.
It said all aspects of its policy had been "strengthened" to protect against Covid and to "ensure the company is able to cruise in the safest, most enjoyable way possible for its guests".
Along with 100% fully vaccinated ships, the update measures also include 100% fresh air in every cabin, a medical team and medical centre on every voyage and rapid PCR testing available onboard each sailing.
Monique Ponfoort, chief executive of Aurora, said the health and safety of guests, staff and crew "remain our number one priority".
"Our health and safety programme has been strengthened and will be precisely followed, including the highest level of pre- cruising preventative measures, the capability for PCR testing on board if required, and a robust response plan and protocols onboard designed to bring peace of mind to all of our guests and crew," she added.