Oh that it was that easy.
Firstly after a jab the nurse has to stay with the subject for 15 mins before releasing them.
Secondly you would have to have thousands of extra nurses to overcome the first problem.
Thirdly, even after you have overcome those problems you would need vast supplies of the vaccine, which we currently do not have.
About 1, or 2 weeks after the first vaccination last month I did a rough calculation in my head, and came to the conclusion that it would take somewhere in the region of 3 to 4 years to vaccinate the entire UK population.