No, the hope is even greater: your doctor orders a fully formed injectable vaccine for the specific cancer that is currently growing in your body. Nobody else has exactly that same mutation, so there is no point in animal trails as the vaccine will only be helpful to you.

This vaccine is a great help to the above: it proves conclusively that the idea is sound. Probably future mRNA vaccines can skip all the phase 1-2 trials and go directly to 3. And for rare diesease they can even skip phase 3.