However unlike the annual flu it does not appear to be changing super dramatically so until shown otherwise eventual herd immunity will drastically reduce the effective virulence.
Obviously a vaccine would be a great thing to have, but there is nothing at all to indicate that this is going to be an annual or seasonal outbreak going forward.
The flu has eight segments. With that you get a substantially higher rate of recombination.
That's why you need a new flu vaccine every year - every year a lot of time is (was?) invested in tracking what flu mutations are appearing and trying to predict which ones will be the main ones next year. Once they've determined what they think are most likely, the vaccines are developed for those. Happily flu mutations mostly impact the protein structures sticking out of the virus wall (the HxNy is an actual description of these proteins, hemagglutinin and neuraminidase), so it's mostly a matter of retargeting an existing set of vaccines rather than creating a whole new vaccine from scratch.