This follows a similar policy announced last week by fellow German operator Hapag-Lloyd Cruises.
Booster recommended now
TUI Cruises strongly recommends a booster for travel before Feb. 23 and urged the shot no later than one week before departure.
Starting Feb. 23, the booster will be required for those 18 and older who received their primary immunisation more than three months before the end of the cruise they're booking. Those who received their primary vaccination but subsequently got COVID-19 have the same status as people with boosters, providing their illness dates back fewer than three months at the end of the cruise they're planning.
Germany is actively encouraging boosters, which are readily available throughout the country. Nevertheless, Hapag-Lloyd Cruises and TUI Cruises are so far the only German cruise lines with a booster mandate.
COVID-19 protocol details vary
While all lines set a high standard, COVID-19 mitigation measures vary in detail among German cruise lines. AIDA, for example, is restricting passengers to 'bubble' excursions for all cruises departing until Feb. 24.