I have concerns that the moderna vaccine doesnt protect against the south african variant compared to pfizer. is there a way to test the antibodies?

While there is concern it may not prevent infection the same is thought for the Pfizer to some degree. Both do seem to prevent severe disease and data on the booster Maderna will debus this fall seems effective in stopping the variant . The antibodies created by the vaccine differ from those of the wild covid illness & tests for them exist but are limited to specialized labs.