Immunogenicity and efficacy of a subcutaneously administered, adjuvanted vaccine containing modified S1 spike protein of SARS-CoV-2 variant C.1.2

Title : Immunogenicity and efficacy of a subcutaneously administered, adjuvanted vaccine containing modified S1 spike protein of SARS-CoV-2 variant C.1.2

Abstract:

During the COVID-19 pandemic, vaccines have produced protective immunity sufficient enough to cause a decrease in hospitalizations and deaths; however, the pandemic continues due to mutational events, predominantly occurring in the S1 sequence of the spike protein of SARS-CoV-2. We have developed a baculovirus-expressed, modified S1 SARS-CoV-2 protein based on the C.1.2 variant, which was first identified in South Africa. This was encapsulated in a vitamin E containing, nonphospholipid liposome (SubATVax™), which was then used to subcutaneously immunize Syrian hamsters with 25 gauge needles. This vaccine, when administered at day 1 generates IgG responses that react to the modified C.1.2 S1 protein; full-length spike proteins from Wuhan-Hu-1, Delta, Omicron BA.1; and the Omicron recombinant variant XBB.1.5 in 100% of the animals. The second dose administered subcutaneously on day 28 demonstrated anamnestic response in the quantitative IgG assay to the Wuhan-Hu-1 spike Receptor Binding Domain (RBD). In addition, antibody IgA and IgM responses in sera were demonstrated. Serum IgG antibody responses to the spike proteins of the modified C.1.2 S1 and full-length spike proteins Wuhan-Hu-1, Delta, Omicron BA.1, and Omicron recombinant XBB.1.5 variants are elevated for over 120 days. Challenge of vaccinated and unvaccinated hamsters at day 126 of the study with an Omicron BA.1 resulted in a difference in weight change and viral load based on the qRT-PCR assay seven days after challenge. We have completed a two-year stability study on the vaccine, and it is stable when stored at 4 degrees C. Photomicrographs and real-time videos of the structures will be presented. In summary, we have developed a new adjuvant system for protein-based vaccines which allows for subcutaneous immunization in a one- or two-dose format.

Biography:

Dr. Wright completed an undergraduate degree in Biology from the University of Virginia in 1972, his M.D. degree from the University of Virginia in 1976, an internship in internal medicine at Columbia P&S Harlem Hospital in New York City in 1977. He then spent 3 years in the Army in Germany seeing patients before returning to the United States to complete a two residency in Internal Medicine, a 3 year research fellowship in Infectious Disease both at Walter Reed Army Medical Center in Washington D.C and tropical medicine training at Walter Reed Army Institute of Research. During his fellowship he set-up the first HIV-1 clinic in the military which he continued to run until 1988. He then left to cofound Univax Biologics, the third biotechnology company in Maryland. In 1993 he cofounded Novavax.  Dr. Wight left Novavax in 2006. He has set-up 3 additional companies LPJP, Inc., David Craig Wright, M.D. Inc. (both California S corporations) and D4 Labs, LLC (California LLC). Dr. Wright has authored or co-authored over 20 issued US patents since 1989.