Paul A. Offit, MD, of The Children's Hospital of Philadelphia returns to JAMA's Q&A series to provide an update on the emergence of COVID-19 variants and their implications for vaccine development, including the Johnson & Johnson vaccine, scheduled for a US Food and Drug Administration VRBPAC hearing on February 26, 2021. Recorded February 11, 2021. Related Article: SARS-CoV-2 Vaccines and the Growing Threat of Viral Variants