What's a Phase? That must be specific to PA. In MN, some people were given priority -- old people, healthcare workers, frontline workers and people with underlying conditions. Maybe Phase is the equivalent of that?
A couple of weeks ago the governor opened vaccines to everyone over 16. It's still hard to get them if you're not in a priority group. My colleague who got sick from his shot gave me incredibly complicated instructions -- you register with all chain drug stores, follow some particular account on Twitter, plus four or five other steps.
In my case, I found that my usual clinic offers a certain number each week that they give to whoever gets appointments first. Appointments can only be made on Thursday and Friday. So last Thursday morning I called the clinic 24 times -- that's how long it took to even get put on hold; the first 23 the call wouldn't even go through. When I did finally reach a human they had about three openings for this Wednesday. I took one, and they sign you up for an appointment exactly two weeks later.