Tier One

The two shot method will start putting a real dent in the virus about April 1.

Two shots of the vaccine make people almost 100% immune, while one shot makes a little more  than 80% of the patients immune. But the one shot method will cover twice as many people. Using the two shot method, 100 out of 100 patients will be immune. Using the one shot method, you would reach 200 people. 160 out of 200 people will become immune. 

I'm not a scientist. There must be a lot more to this discussion. First tier personnel are in great danger, and one shot would not be right for them. I'm in second or third tier, and maybe there is an argument to made.