[Comment] COVID­19 vaccine safety.

In response to the SARS­CoV­2 outbreak, and the resulting COVID­19 pandemic, a global competition to develop an anti­COVID­19 vaccine has ensued. The targeted time frame for initial vaccine deployment is late 2020. The present article examines whether short­term, mid­term, and long­term vaccine safety can be achieved under such an accelerated schedule, given the myriad vaccine­induced mechanisms that have demonstrated adverse effects based on previous clinical trials and laboratory research. It presents scientific evidence of potential pitfalls associated with eliminating critical phase II and III clinical trials, and concludes that there is no substitute currently available for long­term human clinical trials to ensure long­term human safety.