▶ Watch Video: Cruise lines battle CDC in hopes to set sail from U.S. soon A Royal Caribbean cruise has been delayed after eight crew members tested positive for COVID-19. The company’s Odyssey of the Seas ship was set to have its first trip on July 3, but the cruise has been postponed to July 31. In a statement posted on his official Facebook page late Tuesday, President & CEO of Royal Caribbean Michael Bayley said the situation was “two steps forward and one step back.” Bayley said all 1,400 crew members on board Odyssey of the Seas would be considered fully vaccinated on June 18. People getting the Pfizer and Moderna vaccines are considered fully vaccinated two weeks after their second shot. But just days before that date, eight employees had positive COVID-19 tests – two had mild symptoms and six were asymptomatic. All eight have been quarantined and are being closely monitored by a medical team. Now, all crew members will quarantine for 14 days to prevent further infection. Bayley said guests were given several have options to consider, yet he did not say what those options were. “While disappointing, this is the right decision for the health and well-being of our crew and guests,” he said. Just last week, Royal Caribbean’s first cruise in over a year set sail from Miami. But while the the Celebrity Millennium ship was filled with “fully vaccinated” crew and adult guests, two passengers onboard tested positive, according to the company. All adult guests on the cruise were required to show proof of vaccination and a negative COVID-19 test within 72 hours before sailing from St. Maarten. While Republican governors in Florida and Texas are refusing to let companies require passengers to prove they’ve been inoculated, contrary to recommendations from the Centers for Disease Control and Prevention, Royal Caribbean has set up guidelines for passengers departing from other states. On Monday, the company announced that for cruises departing from all U.S. ports — except Florida — all guests 16 years of age or older are required to be fully vaccinated. And starting on August 1, all guests 12 years of age or older must be fully vaccinated. Younger passengers who are not yet eligible for the vaccine will be able to sail with a negative test result and must follow certain protocols. The cruise industry spent more than a year negotiating with the CDC on how to safely protect against COVID-19 and prevent super-spreader events. The CDC guidelines state that 95% of passengers should be fully vaccinated prior to sailing. All people, including port personnel, crew and passengers — even those who are fully vaccinated — are advised to wear masks on ships entering, traveling within or leaving the United States, and in U.S. transportation hubs. This CDC guidance applies to all transportation methods. The CDC says we are still learning how effective the vaccines are against variants of the virus that causes COVID-19 and that early data show the vaccines may work against some variants but could be less effective against others. It is also still unclear how effective vaccines are in people with weakened immune systems and how long the vaccines can protect people. According to the CDC, receiving any of the authorized COVID-19 vaccines would not cause you to test positive on viral tests, which are used to see if you have a current infection. However, people who receive the vaccine may test positive on antibody tests. CBS News has reached out to Royal Caribbean for more information and is awaiting response.