The initial wave of coronavirus vaccines have begun to ship to doctors and pharmacies across the country, and the first group to receive them – healthcare workers and nursing home residents – could conceivably get a shot by the end of the year.

But it will take well into the spring to inoculate everybody who wants one, and several more months after that to significantly mitigate the spread of the virus.

Now at least one cruise line is looking into whether it can do some mitigating of its own.

Norwegian Cruise Line Holdings CEO Frank Del Rio said the cruise company is looking at whether or not being vaccinated can be required of cruise passengers, according to our sister site Travel Weekly .

“It will certainly be a requirement for the crew,” Del Rio told John Lovell, president of Travel Leaders Group, during a Zoom meeting. “But it’s too early to tell whether we have the legal standing to mandate that you take a vaccine to come onboard – lawyers are looking at it as we speak. But there is talk beginning to emerge from different corners of the travel industry, the airlines as well, of requiring some kind of immunity passport demonstrating that you’ve had the virus or been vaccinated so that you are good to go. We have to build confidence in our customers and among ourselves that it’s safe to cruise.”

The airlines are already looking at what is being called a digital health passport , but this stipulation would only tell officials your current COVID-19 status – negative or positive – and not whether you have had the vaccine.

At issue, of course, is exactly what Del Rio suggested – the legality of mandating a vaccine.

Noted labor attorney Deborah Gordon says that, for the most part, private businesses can mandate that their employees be vaccinated although gray areas exist.

Whether a business or even the government can mandate the general public take the vaccine is a different story, Gordon told Fox2 Detroit . And there are many citizens either hesitant to take a vaccine from a medical standpoint or reluctant to be told what to do from a civil liberties standpoint.

Immunity passports are the most likely route to take. And while half of the travelers surveyed recently said they would take the vaccine , mandating it before taking a cruise is completely different.

As of right now, it's just a thought, but time will tell how it all shakes out.

For travel advisor Scott Lara though, a requirement would be key.

"To ensure that passengers and crew remain healthy, I believe it’s important that cruise lines mandate proof that passengers either received the COVID vaccine or have tested negative at least 3 days prior to sailing," Lara told TravelPulse.

But for travel advisor John Maddox, how cruise lines market it will be important.

"I think it is a bit of a slippery slope and cruise lines might be best served to put out some surveys and feelers to see how it might be received," Maddox said. "I do think it is inevitable, but it will, in my opinion, deter some from cruising –especially those that aren't currently avid cruisers. How it is positioned and marketed will be critical. A stamp on a passport or notarized form vs. an app or card might make some difference."