That's why the pharmaceutical industry is not putting all eggs in the vaccine basket (but for the press, it is the only option available).
Therapies with monoclonal antibodies might handle this case, in particular, cocktails of antibodies (like Regeneron, Vir, and Sorrento are making) to reduce the risk of selecting resistant mutants (if you target multiple parts of the virus proteins, they'd have to mutate all together to gain resistance, which is a less likely event).
