Side effects of COVID-19 vaccines: a systematic review and meta-analysis protocol of randomised trials.

INTRODUCTION: SARS-CoV-2 is responsible for a large number of global COVID-19 cases. Strategies such as social isolation, personal hygiene and frequent hand washing have been implemented; however, a protective vaccine is required to achieve sufficient herd immunity to SARS-CoV-2 infection to ultimately control the COVID-19 pandemic. To meet the urgent need for a vaccine, a reduction in the development schedule has been proposed from 10-15 years to 1-2 years. For this reason, this systematic review and meta-analysis protocol aims to compare the side effects, safety and toxicity of COVID-19 vaccines available globally, including their combinations. METHODS AND ANALYSIS: We will select randomised controlled trial-type studies that evaluate the side effects of the COVID-19 vaccine. PubMed, Web of Science, Embase, CINAHL, PsycINFO, LILACS, SCOPUS, ClinicalTrials.gov, International Clinical Trials Registry Platform (ICTRP), medRxiv.org, biorxiv.org, preprints.org and the Cochrane Library will be searched for eligible studies until December 2021. Three reviewers will independently screen and select studies, assess methodological quality and extract data. A meta-analysis will be performed, if possible, and the Grading of Recommendations, Assessment, Development and Evaluations summary of findings will be presented. ETHICS AND DISSEMINATION: This study will review published data, and thus it is unnecessary to obtain ethical approval. The findings of this systematic review will be published in a peer-reviewed journal. PROSPERO REGISTRATION NUMBER: CRD42021231101.