That is not the case - it is for that specific variant of the disease but diseases spread through the entire population have a huge area to mutate in and one of

That is not the case - it is for that specific variant of the disease but diseases spread through the entire population have a huge area to mutate in and one of those mutations could be quite deadly. One of the reason there's a lot of gas behind rolling this vaccine out quickly is that we want to avoid allowing the virus enough time to mutate up some different strains that this vaccine isn't effective in preparing us for since that makes the vaccine far less effective overall.