WHO and its partners are committed to accelerating the development of COVID-19 vaccines while maintaining the highest standards on safety. In the past, vaccines have been developed through a series of steps that can take many years. Now, given the urgent need for COVID-19 vaccines, unprecedented financial investments and scientific collaborations are changing how vaccines are developed. This means that some of the steps in the research and development process have been happening in parallel, while still maintaining strict clinical and safety standards. For example, some clinical trials are evaluating multiple vaccines at the same time. However, this does not make the studies any less rigorous…more