Do you mean like "Efficacy of Pfizer/BioNTech Covid vaccine slips to 84% after six months, data show" (https://www.statnews.com/2021/07/28/efficacy-of-pfizer-biont...) or "Covid-19 Vaccine Efficacy: What Do the Numbers Really Mean?" (https://www.wsj.com/articles/covid-19-vaccine-efficacy-what-...)? Or did you have something else in mind?
I thought this was pretty well-discussed as VRBPAC/ACIP began to review the data guiding their third dose/booster recommendations but maybe I've misunderstood.