We don't really know yet how far the virus can mutate and stay highly infectious. We could get lucky and be able to use the current vaccines for a long time, or

We don't really know yet how far the virus can mutate and stay highly infectious. We could get lucky and be able to use the current vaccines for a long time, or we might need to rework them pretty soon (it's already being done or course, but we don't know how necessarily it will be to deploy the modified vaccines).