%0 Journal Article
%T Interventional Study of Nonpharmaceutical Measures to Prevent COVID-19 Aboard Cruise Ships.
%A Mouchtouri VA
%A Kourentis L
%A Anagnostopoulos L
%A Koureas M
%A Kyritsi M
%A Kontouli KM
%A Kalala F
%A Speletas M
%A Hadjichristodoulou C
%J Emerg Infect Dis
%V 30
%N 5
%D 2024 May
%M 38666667
%F 16.126
%R 10.3201/eid3005.231364
%X Cruise ships carrying COVID-19-vaccinated populations applied near-identical nonpharmaceutical measures during July-November 2021; passenger masking was not applied on 2 ships. Infection risk for masked passengers was 14.58 times lower than for unmasked passengers and 19.61 times lower than in the community. Unmasked passengers' risk was slightly lower than community risk.