Breakthrough in COVID-19 Vaccine Development: Recombinant Protein Subunit Vaccines Show Promising Results

Scientists at the University of Hawaii at Manoa have made a significant breakthrough in the development of COVID-19 vaccines, publishing a new report on the effectiveness of recombinant protein subunit vaccines. According to the researchers, these vaccines have shown remarkable speed in development, with several COVID-19 vaccines receiving FDA and EMA approval for emergency use in record time. Despite challenges in achieving global recipient coverage, especially in resource-poor areas, the researchers have made significant strides in creating a dry-thermostabilized vaccine that can be deployed without refrigeration.

Key Takeaways:

• The researchers developed a recombinant protein subunit vaccine using CoVaccine HT adjuvant that elicited a broad-spectrum IgG response and high neutralizing antibody (NtAb) titers against SARS-CoV-2 prototype and variants of concern.
• The vaccine candidates demonstrated a Th1 biased, humoral and cellular immune response in outbred mice, with dose-response experiments indicating that NtAb titers increased with antigen dose but not adjuvant dose.
• The study laid the immunological foundation for the development of a dry-thermostabilized vaccine, which is deployable without refrigeration, addressing a significant challenge in vaccine distribution.
• The vaccine developers, led by Albert To, demonstrated the feasibility of using CoVaccine HT adjuvant, an oil-in-water nanoemulsion compatible with lyophilization, to enhance vaccine efficacy.
• The research, published in Vaccine: X, has significant implications for the development of COVID-19 vaccines and may contribute to the efforts to generate sufficient herd immunity and reduce transmission of the SARS-CoV-2 virus.

Statistics:

• The researchers obtained high neutralizing antibody (NtAb) titers against SARS-CoV-2 prototype and variants of concern, specifically B.1.351 (Beta) and P.1. (Gamma), using the recombinant protein subunit vaccine candidates.
• The vaccine elicited a broad-spectrum IgG response, with dose-response experiments indicating that NtAb titers increased with antigen dose but not adjuvant dose.
• The study demonstrated the feasibility of using CoVaccine HT adjuvant, which is compatible with lyophilization, to enhance vaccine efficacy and stability.

Sources:

• Recombinant protein subunit SARS-CoV-2 vaccines formulated with CoVaccine HT adjuvant induce broad, Th1 biased, humoral and cellular immune responses in mice. Vaccine: X, 2021, 9():100126. The publisher for Vaccine: X is Elsevier.
• NewsRx. Research from University of Hawaii at Manoa Provide New Insights into COVID-19 (Recombinant protein subunit SARS-CoV-2 vaccines formulated with CoVaccine HT adjuvant induce broad, Th1 biased, humoral and cellular immune responses in mice). Vaccine Weekly. December 15, 2021; p 840.