Curious about how #COVID19 vaccines were developed and approved? Through the ACTIV program, NIH is working with many partners to develop a safe and effective vaccine for COVID-19. Learn how candidate vaccines are tested through the different phases of clinical trials - tune in for this brief but insightful video! For more information about NIH's COVID-19 efforts, visit: https://covid19.nih.gov/ or follow @nihgov on Instagram.