HYBRID EVENT: You can participate in person at Baltimore, Maryland, USA or Virtually from your home or work.
David Craig Wright, Speaker at Vaccines Conferences
D4 Labs, LLC , United States
Title : Immunogenicity and Efficacy of a Subcutaneously Administered, Adjuvanted Vaccine Containing Modified S1 Spike Protein of SARS-CoV-2 Variant C.1.2


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.


Dr. Wright studied Biology at the University of Virginia (1968-1972) and attended the University of Virginia Medical School (1972-1976). He completed his internship at Harlem Hospital in New York City (1976-1977), his residency in Internal Medicine at Walter Reed Army Medical Center (WRAMC) (1980-1982), and his three-year infectious disease fellowship at WRAMC (1983-1985), working in the laboratory of Dr. Gerald Sadoff at Walter Reed Army Institute of Research. He has been an Infectious Disease practitioner since 1985 and has co-founded three companies: Univax Biologics, Novavax, and D4 Labs, LLC. Dr. Wright holds 20 U.S. patents and has numerous publications.