According to the WHO, efficacy refers to vaccine performance in controlled studies whereas effectiveness refers to performance in the broader population [0]. Da

According to the WHO, efficacy refers to vaccine performance in controlled studies whereas effectiveness refers to performance in the broader population [0]. Data aggregated by JHU appears more or less consistent with estimates of vaccine efficacy [1]. [0] https://www.who.int/news-room/feature-stories/detail/vaccine-efficacy-effectiveness-and-protection https://www.who.int/news-room/feature-stories/detail/vaccine... [1] https://coronavirus.jhu.edu/pandemic-data-initiative/data-outlook/the-state-of-state-level-breakthrough-case-reporting https://coronavirus.jhu.edu/pandemic-data-initiative/data-ou...