The vaccines we're seeing are only 10% effective against the SA strain.
This is not accurate.
The AZ vaccine was only 10% effective in a study in SA. That's the only one that was shown to be vastly less effective.
The Pfizer vaccine is believed to be effective against the SA variant (though I think it used In Vitro studies) and there are lots of other vaccines on the way. We will get this under control but it will be a long slow process over several years.