Is there a good way to test that an mRNA vaccine batch was stored improperly and in result has reduced efficiency? In the US supply chain may not be a problem,

Is there a good way to test that an mRNA vaccine batch was stored improperly and in result has reduced efficiency? In the US supply chain may not be a problem, but if exported, in some countries it's possible that people will get near useless vaccine shots, thus hurting reputation of mRNA vaccines in general.