Ex, it's true that it's only one batch, but many injections can be made from that single batch. I don't know how many, or that each batch is the same size. I would suspect that once the cancer's under control, the size of each dose could be diminished permitting more doses. Further usage may show that the dose can be reduced and still elicit the same response permitting many more doses.
I certainly don't know, but believe that there are companies who've developed bioreactors that potentially could duplicate the vaccine if sufficient vaccine was retained to allow them to operate. I don't believe that NWBO has this capability, but others specialize in only doing that.
Gary