In a letter issued to the cruise industry on Wednesday, the CDC said that voyages can resume as early as summer if the vast majority of passengers and crew are vaccinated. If ships can show that 98 percent of crew and 95 percent of passengers are vaccinated, they won’t need to do passenger-less test cruises beforehand, the letter said. Requirements around testing and quarantining have also been relaxed. “We acknowledge that cruising will never be a zero-risk activity,” a CDC official wrote in the letter. CDC spokesperson Caitlin Shockey later narrowed down the timeline to mid-July, assuming that cruise lines are on time in submitting documents called port agreements, which show they are coordinating with local health authorities. A rep for trade group Cruise Lines International Association called the announcement a “positive progression.” U.S. cruises have been on pause since April 9, 2020.