First in line would be a half million military personnel, and a half million civilian medical workers. Next, as many as 10 million emergency health care and rescue workers who'd be first to respond to a bioterror attack. After that, the vaccine would be available to anyone who wants it, accompanied by stern warnings about the risks.
"Why is this such an agonizing decision? It's an extremely difficult decision for the President to make because it involves weighing the risk of a possible terrorist use of smallpox, which is almost impossible to quantify, against the known risks of the vaccine, which are substantial," says Jonathan Tucker, a smallpox expert
Smallpox is highly contagious, hard to contain and kills a third of its victims. Moreover, the vaccine itself is riskier than any other on the market.
Out of every million people who get the shot, two to three people will die. Nationwide, that could translate to hundreds of deaths and thousands of life threatening illnesses caused by the vaccine.
All 50 states plus the three largest cities - New York, Los Angeles and Chicago - are scrambling to meet a Monday deadline to submit plans for giving inoculations.
One frontline health care worker says the phased-in approach makes sense.
"The initial people are going to be test subjects or guinea pigs," says Dr. Martin Blaser, Chairman of the Department of Medicine at NYU Medical Center and an infectious disease specialist.
"If we vaccinate a half million people we'll learn something about the logistics, the medical complications, we'll learn something about the spread of the vaccine from vaccinated people to unvaccinated we'll learn something about the complications," Blaser tells Attkisson.
Even if you were vaccinated as a child, the protection has likely worn off. So hundreds of millions of people will have to weigh the risks and benefit of getting the shot. What's been a difficult decision for the President will likely be difficult for the public too.