As the Delta variant of SARS-CoV-2 is causing breakthrough infections in some vaccinated people around the world, scientists at Northwestern Medicine are developing and studying potential next-generation COVID-19 vaccines that could be more effective at preventing and clearing breakthrough infections. Pablo Penaloza-MacMaster, assistant professor of Microbiology-Immunology at Feinberg, discusses recent studies from his lab that aim to improve current COVID-19 vaccines.