Efficacy of the third dose of COVID-19 vaccine: a systematic review and meta-analysis

Abstract

Review question / Objective: To investigate the immune response and related clinical outcomes of healthy adults who received coronavirus vaccine booster compared with those who did not receive the vaccine booster. Condition being studied: The COVID-19 pandemic, which has spread since 2019, has created a huge disease and economic burden on the world. A large number of clinical trials have verified the effectiveness of COVID-19 vaccine. Previous studies have found that the serum conversion rate and antibody level of those vaccinated after the first two doses of COVID-19 vaccine continue to decrease, and the efficacy of the vaccine will decrease over time after the first two doses. Therefore, in order to maintain the protective efficacy of the vaccine, The need for a vaccine booster shot to achieve the expected goal of long-term effective prevention of the novel coronavirus has become a focus of discussion around the world.