1 Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA; Department of Medicine, Duke University School of Medicine, Durham, NC 27710, USA.
2 Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC 27710, USA; Department of Pediatrics, Duke University School of Medicine, Durham, NC 27710, USA. Electronic address: genevieve.fouda@duke.edu.