These vaccines have demonstrated equivalent vaccine efficacy across all racial and ethnic backgrounds. This will continue to be tracked over the next two years. Stanford Medicine is encouraged by the high level of racial and ethnic diversity represented in the Pfizer and Moderna clinical trials. Pfizer has stated that approximately 42% of its 44,392 participants in its global COVID-19 vaccine clinical trials have a diverse background. Moderna has reported that it recruited more than 11,000 people from communities of color — 37% of its cohort — as well as 7,000 people over the age of 65. The Moderna vaccine had 100% efficacy in those aged 65 and older, and 100% efficacy in communities of color. Learn more about clinical trials at the US Food & Drug Administration website.