SARS-CoV-2 virus: Vaccines in development

The ongoing COVID-19 pandemic, caused by SARS-CoV-2, is an unprecedented challenge to humanity. Global herd immunity may be necessary before resumption of normal economic and societal activities. Since the beginning of the outbreak, the development of COVID-19 vaccines has proceeded at record speed using nearly all available platforms or strategies to maximize vaccine success. A total of 42 vaccine candidates have now entered clinical trials and encouraging data from several vaccine candidates in phase 1 or 2 clinical trials have been reported. In this review, we examine current COVID-19 vaccine candidates, discuss their strengths and weaknesses, summarize published clinical data and analyze future challenges.