Royal Caribbean International will require that passengers over the age of 2 to provide a negative coronavirus test before boarding ships with itineraries for five nights or longer in U.S. waters.
This policy will be in place starting Saturday and lasting through Aug. 31 and was announced "in an abundance of caution." The cruise line will accept both PCR and antigen negative results.
Before Saturday, vaccinated passengers were not required to show a negative test, spokesperson Lyan Sierra-Caro told USA TODAY. The added precaution comes as the delta variant continues to spread across the country.
The test must be administered no more than three days before boarding and passengers must show proof of their negative test result at check-in.
"All other testing requirements and policies are still in place This is an additional layer of precaution to ensure the safety of everyone onboard," Royal Caribbean said in a statement provided by Sierra-Caro. "We will continue to monitor public health circumstances as they evolve and make necessary adjustments to our protocols."
The news came on the same day that six passengers tested positive for the COVID-19 virus on a 7-night cruise on Royal Caribbean's Adventure of the Seas that departed from Nassau last Saturday. Four passengers who tested positive were vaccinated, and two who tested positive were unvaccinated minors.
All passengers on board were required to show proof of a negative coronavirus test before boarding in the Bahamas.
This article originally appeared on USA TODAY: Royal Caribbean adds test requirement to board US cruises through August