New panel of antibodies specific to SARS-CoV-2 variants available for vaccine researchers

PATH, Texas Children’s Hospital Center for Vaccine Development, Baylor College of Medicine, and the Medicines and Healthcare products Regulatory Agency (MHRA) have collaborated to provide variant-specific monoclonal antibodies (mAbs) against the receptor-binding domain (RBD) of SARS-CoV-2 variants. These mAbs can support researchers globally during the characterization and development of vaccines for current and evolving variants of SARS-CoV-2.

Through this collaboration, scientists from Texas Children’s Hospital Center for Vaccine Development and Baylor’s Protein and Monoclonal Antibody Production Core produced high-quality recombinant SARS-CoV-2 RBD proteins (WA01 [Wuhan], Delta and Omicron BA1 strains), vaccinated mice, and tested selected mAbs for their functionality. The use of various techniques to characterize the binding sites and pseudovirus neutralization helped establish a toolbox of mAbs with identified key epitopes within the RBD and discriminate vaccine antigens. Selected hybridoma cultures were shipped to PATH for further validation, scale-up production, and distribution. These mAbs can potentially be used by manufacturers to quantify different variants of the spike protein in vaccine formulations. These efforts were led by Dr. Jeroen Pollet, assistant professor of pediatrics-tropical medicine at Baylor and Dr. Dean Edwards, professor of molecular and cellular biology at Baylor.

“This panel of well-characterized murine monoclonal antibodies is an ideal and valuable tool during the development of the new generation of broad-spectrum pan-corona vaccines,” said Dr. Pollet. “Our vaccine center is privileged to contribute to this collaborative project and support the global access of valuable research reagents.”

A full characterization report will be provided along with antibodies detailing the specificity across different antigens and vaccine formats, based on data produced by Baylor, Texas Children’s, PATH, and the New York State Department of Health, Wadsworth Center.

Although more recent variants of concern, such as Omicron, have largely replaced the WA01 SARS-CoV-2 (Wuhan) variant in global circulation, existing first-generation COVID-19 vaccines continue to provide a protective immune response against SARS-CoV-2 variants.

As SARS-CoV-2 continues to evolve, generating new circulating variants, development of bi- or trivalent vaccines—which can induce SARS-CoV-2 antibodies against multiple variants—can improve the breadth of SARS-CoV-2 protection.

To help ensure equitable access, the antibodies generated are available at the cost of shipping for use by vaccine researchers and manufacturers who are developing vaccines for use in low- and middle-income countries. Providing these open resources is one component of PATH’s ongoing work with partners to advance the development of vaccines that are low-cost, broadly protective, and tailored for use in low-resource settings.

The following antibodies are available from the MHRA via their online repository and distribution center (www.nibsc.org or contact cfar@nibsc.org).

• mAb 486 SARS-CoV-2 RBD Wuhan variant specific
• mAb 215 SARS-CoV-2 RBD Delta variant specific
• mAb 304 SARS-CoV-2 RBD Omicron variant specific
• mAb 175 SARS-CoV-2 RBD cross-reactive

“The primary aim of this collaboration is to rapidly advance research and development of vaccine candidates targeting these variants by providing the global community of vaccine researchers and manufacturers a boost in their efforts to design, develop, and test vaccines,” said Dr. Jessica White, PATH's Senior Scientist, Vaccine Formulation.

Development of these antibodies and data were supported via funding to PATH from the Bill & Melinda Gates Foundation.

About PATH
PATH is a global nonprofit dedicated to achieving health equity. With more than 40 years of experience forging multisector partnerships, and with expertise in science, economics, technology, advocacy, and dozens of other specialties, PATH develops and scales up innovative solutions to the world’s most pressing health challenges.

About Baylor
Baylor College of Medicine (www.bcm.edu) in Houston is recognized as a health sciences university and is known for excellence in education, research, and patient care. It is ranked 22nd among medical schools for research and 16th for primary care by U.S. News & World Report. Baylor is listed 20th among all U.S. medical schools for National Institutes of Health funding and No. 1 in Texas. Located in the Texas Medical Center, Baylor has affiliations with seven teaching hospitals and jointly owns and operates Baylor St. Luke’s Medical Center, part of St. Luke’s Health. Currently, Baylor has more than 3,000 trainees in medical, graduate, nurse anesthesia, physician assistant, orthotics, and genetic counseling, as well as residents and postdoctoral fellows.

ABOUT TEXAS CHILDREN’S HOSPITAL CENTER FOR VACCINE DEVELOPMENT

Texas Children’s Hospital Center for Vaccine Development is one of the leading vaccine development centers in the world. Established in Washington, DC, as the Sabin Vaccine Institute Product Development Partnership (PDP) in the year 2000 and after relocating to the Texas Medical Center in 2011, it rebranded as Texas Children’s Center for Vaccine Development. For the past two decades, it has acquired an international reputation as a non-profit PDP, advancing vaccines for poverty-related neglected tropical diseases and emerging infectious diseases of pandemic importance. In addition, it builds and strengthens capacity for vaccine development locally and with foreign nations and leads global efforts to guide and influence vaccine policy and advocacy through “vaccine diplomacy” as an international bridge for peace and vaccine development capacity.

About the MHRA
The Medicines and Healthcare products Regulatory Agency (MHRA) regulates medicines, medical devices, and blood components for transfusion in the UK. The MHRA is responsible for making sure these products meet set standards for safety, quality, and effectiveness. The MHRA is an Executive Agency of the Department of Health and Social Care. www.gov.uk/mhra

National Institute of Biological Standards and Control (NIBSC) standards, from the MHRA, are available globally to set the quality of biological medicines. The MHRA develops and produces over 90% of the World Health Organization International Standards in use around the world and supplies the healthcare sector with a variety of reagents which are used to develop, control, and calibrate biological assays. The MHRA also offers NIBSC contract and control testing services. www.nibsc.org