The U.S. Centers for Disease Control (CDC) and Prevention on Friday issued new guidance to the cruise ship industry, including the need for COVID-19 vaccinations, a necessary step before passenger voyages can resume.

The new technical instructions, the first update since October, include increasing from weekly to daily reporting frequency of COVID-19 cases and illnesses and implementing routine testing of all crew based on a ship’s COVID-19 status and establishing a plan and timeline for vaccination of crew and port personnel.

“COVID-19 vaccination efforts will be critical in the safe resumption of passenger operations,” the CDC said.

CDC said the next phase of the CDC’s conditional sail order will include simulated voyages to will allow crew and port personnel to practice new COVID-19 operational procedures with volunteers before sailing with passengers.

“CDC is committed to working with the cruise industry and seaport partners to resume cruising when it is safe to do so, following the phased approach outlined” in October’s conditional sail order,” the agency said.

It did not specify a date for the resumption of cruise operations from U.S. ports despite calls from the industry for planning for a phased resumption by the beginning of July. The CDC said it will issue additional guidance before it will allow cruises to resume.

The Cruise Lines International Association, which represents Carnival Corp, Norwegian Cruise Line and Royal Caribbean Cruises and others had pleaded with CDC to issue new guidance, saying in a March 24 statement the “lack of any action by the CDC has effectively banned all sailings in the largest cruise market in the world.” It did not immediately comment on Friday.

The group had said the prior conditional sail order issued in October was “outdated” and “does not reflect the industry’s proven advancements and success operating in other parts of the world, nor the advent of vaccines, and unfairly treats cruises differently. Cruise lines should be treated the same as other travel, tourism, hospitality, and entertainment sectors.”

This article was written by David Shepardson from Reuters and was legally licensed through the Industry Dive publisher network. Please direct all licensing questions to legal@industrydive.com.

Photo Credit: A file photo of the Carnival Miracle is shown in Alaska. The CDC declined to issue a date for the resumption of sailings. Carnival Cruise