We accept a mixed vaccination series consisting of doses from different manufacturers, as long as your vaccine series meets the following requirements: Must consist of at least two doses of vaccines that are fully approved or authorized for emergency use by the U.S. FDA, the European Medicines Agency, and the WHO. The two doses must be administered at least 28 days apart* The final dose must be completed before sailing. Please note, boosters are effective immediately once administered. Mixed vaccines may not be accepted at all ports of call. Guests who are vaccinated with a mixed series may not be allowed to go ashore at these ports, or may need to undergo additional testing if they wish to go ashore.