Please let me make it clear. I only posted about Pfizer's as they have been the first company to publicly state they have a vaccine with evidence of efficacy. I am not holding them up as the best , simply the first. World wide there are many other teams looking at way of defeating Covid-19, and it will be vitally important to have more than one type of solution.
As yet there is no way of determining if one solution is better than another, so no one - not even the different development teams can rank the comparative efficacy.
Unless there is a concern about negative interactions between different solutions administered to a person, I can see no reason to refuse one brand, to wait for a second to come on stream.
Unnecessary delays in commencing a course gives the virus more chance to adapt.
And now for the controversial point:-
I also believe that if the vaccine is confirmed as having a 90% or greater success rate, vaccination should be made compulsory except where professional medical counter concerns exist.