Breadth of SARS-CoV-2 Neutralization and Protection Induced by a Nanoparticle Vaccine

Thomas N. Denny, MSc, M.Phil, is the Chief Operating Officer of the Duke Human Vaccine Institute (DHVI), Associate Dean for Duke Research and Discovery @RTP, and a Professor of Medicine in the Department of Medicine at Duke University Medical Center. He is also an Affiliate Member of the Duke Global Health Institute. Previously, he served on the Health Sector Advisory Council of the Duke University Fuquay School of Business. Prior to joining Duke, he was an Associate Professor of Pathology, Laboratory Medicine and Pediatrics, Associate Professor of Preventive Medicine and Community Health and Assistant Dean for Research in Health Policy at the New Jersey Medical School, Newark, New Jersey. He has served on numerous committees for the NIH over the last two decades and currently is the principal investigator of an NIH portfolio in excess of 65 million dollars. Mr. Denny was a 2002-2003 Robert Wood Johnson Foundation Health Policy Fellow at the Institute of Medicine of the National Academies (IOM). As a fellow, he served on the US Senate Health, Education, Labor and Pensions Committee with legislation/policy responsibilities in global AIDS, bioterrorism, clinical trials/human subject protection and vaccine related-issues.

As the Chief Operating Officer of the DHVI, Mr. Denny has senior oversight of the DHVI research portfolio and the units/teams that support the DHVI mission. He has extensive international experience and previously was a consultant to the U.S. Centers for Disease Control and Prevention (CDC) for the President’s Emergency Plan for AIDS Relief (PEPFAR) project to oversee the development of an HIV and Public Health Center of Excellence laboratory network in Guyana. In September 2004, the IOM appointed him as a consultant to their Board on Global Health Committee studying the options for overseas placement of U.S. health professionals and the development of an assessment plan for activities related to the 2003 PEPFAR legislative act. In the 1980s, Mr. Denny helped establish a small laboratory in the Republic of Kalmykia (former Soviet Union) to improve the care of children with HIV/AIDS and served as a Board Member of the Children of Chernobyl Relief Fund Foundation. In 2005, Mr. Denny was named a consulting medical/scientific officer to the WHO Global AIDS Program in Geneva. He has also served as program reviewers for the governments of the Netherlands and South Africa as well as an advisor to several U.S. biotech companies. He currently serves as the Chair of the Scientific Advisory Board for Grid Biosciences.

Mr. Denny has authored and co-authored more than 200 peer-reviewed papers and serves on the editorial board of Communications in Cytometry and Journal of Clinical Virology. He holds an M.Sc in Molecular and Biomedical Immunology from the University of East London and a degree in Medical Law (M.Phil) from the Institute of Law and Ethics in Medicine, School of Law, University of Glasgow. In 1991, he completed a course of study in Strategic Management at The Wharton School, University of Pennsylvania. In 1993, he completed the Program for Advanced Training in Biomedical Research Management at Harvard School of Public Health. In December 2005, he was inducted as a Fellow into the College of Physicians of Philadelphia, the oldest medical society in the US.

While living in New Jersey, Mr. Denny was active in his community, gaining additional experience from two publicly elected positions. In 2000, Mr. Denny was selected by the New Jersey League of Municipalities to Chair the New Jersey Community Mental Health Citizens’ Advisory Board and Mental Health Planning Council as a gubernatorial appointment.

The activities of the Ferrari Laboratory are based on both independent basic research and immune monitoring studies. The research revolves around three main areas of interest: class I-mediated cytotoxic CD8+ T cell responses, antibody-dependent cellular cytotoxicity (ADCC), gene expression in NK and T cellular subsets upon infection with HIV-1. With continuous funding over the last 11 years from the NIH and Bill & Melinda Gates Foundation along with many other productive collaborations within and outside of Duke, the Ferrari Lab has expanded its focus of research to include the ontogeny of HIV-1 specific immune responses that work by eliminating HIV-1 infected cells and how these can be induced by AIDS vaccine candidates.

My research focuses on the interactions of T cells and B cells during infection or following vaccination. I am particularly interested in the inter- and intracellular events that take place within germinal centers, the anatomic site of antibody evolution during an immune response.

Dr. Montefiori is Professor and Director of the Laboratory for HIV and COVID-19 Vaccine Research & Development in the Department of Surgery, Division of Surgical Sciences at Duke University Medical Center. His major research interests are viral immunology and HIV and COVID-19 vaccine development, with a special emphasis on neutralizing antibodies.

Multiple aspects of HIV-1 neutralizing antibodies are studied in his laboratory, including mechanisms of neutralization and escape, epitope diversity among the different genetic subtypes and geographic distributions of the virus, neutralizing epitopes, requirements to elicit protective neutralizing antibodies by vaccination, optimal combinations of neutralizing antibodies for immunoprophylaxis, and novel vaccine designs for HIV-1. Dr. Montefiori also directs large vaccine immune monitoring programs funded by the NIH and the Bill & Melinda Gates Foundation that operate in compliance with Good Clinical Laboratory Practices and has served as a national and international resource for standardized assessments of neutralizing antibody responses in preclinical and clinical trials of candidate HIV vaccines since 1988.

At the onset of the COVID-19 pandemic he turned his attention to SARS-CoV-2, with a special interest in emerging variants and how they might impact transmission, vaccines and immunotherapeutics. His rapid response to emerging SARS-CoV-2 variants of concern provided some of the earliest evidence of the potential risk the variants pose to vaccines. In May 2020, his laboratory was recruited by the US Government to lead the national neutralizing antibody laboratory program for COVID-19 vaccines.

His laboratory utilizes FDA approved validated assay criteria to facilitate regulatory approvals of COVID-19 vaccines. He has published over 750 original research papers that have helped shape the scientific rationale for antibody-based vaccines.

Kevin O. Saunders, PhD, graduated from Davidson College in 2005 with a Bachelor of Science in biology. At Davidson College, he trained in the laboratory of Karen Hales, PhD, identifying the genetic basis of infertility. Saunders completed his doctoral research on CD8+ T cell immunity against HIV-1 infection with Georgia Tomaras, PhD, at Duke University in 2010. He subsequently trained as a postdoctoral fellow in the laboratories of Drs. Gary Nabel and John Mascola at the National Institutes of Health (NIH) National Institute of Allergy and Infectious Diseases (NIAID) Vaccine Research Center.

In 2014, Saunders joined the faculty at the Duke Human Vaccine Institute as a medical instructor. In this role, he analyzed antibody responses in vaccinated macaques, which led to the identification of glycan-dependent HIV antibodies induced by vaccination. Dr. Saunders was appointed as a non-tenure track assistant professor of surgery and the director of the laboratory of protein expression in the Duke Human Vaccine Institute in 2015. He successfully transitioned to a tenure-track appointment in 2018 and was later promoted to the rank of associate professor in surgery in 2020. In 2022, Saunders became an associate professor with tenure. He rose to the rank of professor with tenure in 2024 and was subsequently awarded the Norman L. Letvin, MD Professor in Immunology and Infectious Diseases Research in Surgery and the Duke Human Vaccine Institute distinguished professorship. Saunders previously served as DHVI's associate director of research, director or research, and currently serves as the associate director for DHVI. Additionally, Saunders serves as the faculty chairperson for DHVI's Diversity, Equity, and Inclusion Committee.

Saunders has given invited lectures at international conferences such as HIVR4P and the Keystone Symposia for HIV Vaccines. He has authored book chapters and numerous journal articles and holds patents on vaccine design concepts and antiviral antibodies. As a faculty member at Duke, Saunders has received the Duke Human Vaccine Institute Outstanding Leadership Award and the Norman Letvin Center For HIV/AIDS Vaccine Immunology and Immunogen Discovery Outstanding Investigator Award, Ruth and A. Morris Williams Faculty Research Prize, and the Duke Medical Alumni Emerging Leader Award. His current research interests include vaccine and antibody development to combat HIV-1, coronavirus, and other emerging viral infections.

About the Saunders Laboratory
The Saunders laboratory aims to understand the immunology of broadly protective antibodies and the molecular biology of their interaction with viral glycoprotein. The laboratory utilizes single B cell PCR, bulk B cell sequencing, and antigen-specific next-generation sequencing to probe the antibody repertoire during natural infection and after vaccination. The lab's overall goal is to develop protective antibody-based vaccines; therefore, the laboratory is divided into two sections–Immunoprofiling and Vaccine/Therapeutics design. They employ a reverse vaccinology approach to vaccine design where they study broadly protective antibodies in order to design vaccines that elicit such antibodies. To elicit broadly protective antibody responses, the Saunders laboratory utilizes epitope-focused nanoparticle vaccines. While eliciting broad protection is their overall goal, they are also interested in the immunologic mechanisms that make the vaccines successful.

Anti-glycan HIV-1 antibody biology. Their research premise is that vaccine-elicited antibodies will broadly neutralize HIV-1 if they can bind directly to the host glycans on Env. However, Env glycans are poorly immunogenic and require specific targeting by a vaccine immunogen to elicit an antibody response. Using this technique they identified two monoclonal antibodies from HIV Env vaccinated macaques called DH501 and DH502 that bind directly to mannose glycans and to HIV-1 envelope (Env). They have characterized these antibodies using glycan immunoassays, antibody engineering, and x-ray crystallography to define the mechanisms of Env-glycan interaction by these antibodies. Glycan-reactive HIV antibodies have mostly been found in the repertoire as IgG2 and IgM isotypes—similar to known natural glycan antibodies. Therefore they are examining whether vaccines mobilize antibodies from the natural glycan pool that affinity mature to interact with HIV-1 envelope. During this work, they discovered that Man₉GlcNAc₂ is the glycan preferred by early precursors in broadly neutralizing antibody lineages. They translated this finding into a vaccine design strategy that they have termed “glycan learning.” This approach modifies the number of glycans and type of glycosylation of HIV-1 Env immunogens to be optimal for engagement of the precursor antibody. The Env glycosylation sites and glycan type are then modified on subsequent Env immunogens to select antibodies that are maturing towards a broadly neutralizing phenotype. They have developed cell culture procedures and purification strategies combined with mass spectrometry analyses to create Env immunogens with specific glycosylation profiles. While the overall goal is to elicit protective neutralizing antibodies in vivo, they use these Env antigens in vitro to investigate the biology of B cell receptor engagement. 

HIV-1 Sequential vaccine design. The discovery of lineages of broadly neutralizing antibodies in HIV-infected individuals has provided templates for vaccine design. Utilizing viral sequences from individuals that make broadly neutralizing antibodies, we further engineer the viral protein to preferentially bind the desired type of antibody. The Saunders lab partners heavily with structural biologists and bioinformaticians to design optimized vaccine immunogens for in vitro and preclinical testing. They are investigating the hypothesis that broadly neutralizing antibodies can be engaged with envelope immunogens specifically designed to target them, and that engineered envelopes can select for the broadly neutralizing antibody precursors to develop into a broadly neutralizing antibody. They examine antibody responses in vaccinated humanized mice and monkeys to discern if the vaccine elicits antibodies that are similar to the known human broadly neutralizing antibody targets. Vaccines that are effective in animal models are translated for manufacturing and evaluation in Phase I clinical trials.

Pancoronavirus vaccine development. During the COVID-19 pandemic, the Saunders lab and DHVI as a whole worked to isolate broadly neutralizing antibodies against SARS-CoV-2 and related viruses. These antibodies then served as a template for the development of receptor binding domain nanoparticle vaccines we call RBD-scNP. These vaccines protected monkeys and mice from SARS-CoV-2 and animal coronaviruses. This vaccine has been translated to GMP manufacturing and will be examined in a Phase I clinical trial. The lab continues to apply similar approaches against other targets on coronaviruses to ultimately generate protective immunity against most coronaviruses. The lab explores different delivery methods including slow-release technology and nucleoside-modified mRNA delivery.

Taken together, our research program is an interdisciplinary approach to understanding the molecular biology underlying antibody recognition of viral glycoproteins in order to produce protective vaccines.

Barton F. Haynes, M.D. is the Frederic M. Hanes Professor of Medicine and Immunology, and Director of the Duke Human Vaccine Institute. Prior to leading the DHVI, Dr. Haynes served as Chief of the Division of Rheumatology, Allergy and Clinical Immunology, and later as Chair of the Department of Medicine. As Director of the Duke Human Vaccine Institute, Bart Haynes is leading a team of investigators working on vaccines for emerging infections, including tuberculosis, pandemic influenza, emerging coronaviruses, and HIV/AIDS.

To work on the AIDS vaccine problem, his group has been awarded two large consortium grants from the National Institutes of Health (NIH), National Institute of Allergy and Infectious Diseases (NIAID) known as the Center for HIV/AIDS Vaccine Immunology (CHAVI) (2005-2012), and the Center for HIV/AIDS Vaccine Immunology-Immunogen Discovery (CHAVI-ID) (2012-2019) to conduct discovery science to speed HIV vaccine development. In July 2019, his team received the third of NIH “CHAVI” awards to complete the HIV vaccine development work - CHAV-D.

Since the beginning of the COVID-19 pandemic, Haynes and the DHVI Team has been working non-stop to develop vaccines, rapid and inexpensive tests and therapeutics to combat the pandemic. Since March 2020, he has served as a member of the NIH Accelerating COVID-19 Therapeutic Interventions and Vaccines (ACTIV) committee to advise on COVID-19 vaccine development, and served as the co-chair of the ACTIV subcommittee on vaccine safety. Haynes is the winner of the Alexander Fleming Award from the Infectious Disease Society of America and the Ralph Steinman Award for Human Immunology Research from the American Association of Immunologists. He is a member of the National Academy of Medicine, National Academy of Inventors and the American Academy of Arts and Sciences.