Abstract
AbstractWith the continued emergence of variants of concern, the global threat of COVID-19 persists, particularly in low- and middle-income countries with limited vaccine access. Protein-based vaccines, such as SCB-2019, can be produced on a large scale at a low cost while antigen design and adjuvant use can modulate efficacy and safety. While effective humoral immunity against SARS-CoV-2 variants has been shown to depend on both neutralization and Fc-mediated immunity, data on the effectiveness of protein-based vaccines with enhanced Fc-mediated immunity is limited. Here, we assess the humoral profile, including antibody isotypes, subclasses, and Fc receptor binding generated by a boosting with a recombinant trimer-tag protein vaccine SCB-2019. Individuals who were primed with 2 doses of the ChAdOx1 vaccine were equally divided into 4 groups and boosted with following formulations: Group 1: 9 μg SCB-2019 and Alhydrogel; Group 2: 9 μg SCB-2019, CpG 1018, and Alhydrogel; Group 3: 30 μg SCB-2019, CpG 1018, and Alhydrogel; Group 4: ChAdOx1. Group 3 showed enhanced antibody FcγR binding against wild-type and variants compared to Groups 1 and 2, showing a dose-dependent enhancement of immunity conferred by the SCB-2019 vaccine. Moreover, from day 15 after vaccination, Group 3 exhibited higher IgG3 and FcγR binding across variants of concerns, including Omicron and its subvariants, compared to the ChAdOx1-boosted individuals. Overall, this highlights the potential of SCB-2019 as a cost-efficient boosting regimen effective across variants of concerns.
Funder
Bill and Melinda Gates Foundation
The Samana Kay MGH Research Scholars fund
Publisher
Springer Science and Business Media LLC
Subject
Pharmacology (medical),Infectious Diseases,Pharmacology,Immunology
Reference27 articles.
1. WHO Coronavirus (COVID-19) Dashboard. https://covid19.who.int/?mapFilter=cases (2023).
2. Nagy, A. & Alhatlani, B. An overview of current COVID-19 vaccine platforms. Comput. Struct. Biotechnol. J. 19, 2508–2517 (2021).
3. Bravo, L. et al. Efficacy of the adjuvanted subunit protein COVID-19 vaccine, SCB-2019: a phase 2 and 3 multicentre, double-blind, randomised, placebo-controlled trial. Lancet 399, 461–472 (2022).
4. Richmond, P. C. et al. Persistence of the immune responses and cross-neutralizing activity with variants of concern following 2 doses of adjuvanted SCB-2019 coronavirus disease 2019 vaccine. J. Infect. Dis. 224, 1699–1706 (2021).
5. Richmond, P. et al. Safety and immunogenicity of S-Trimer (SCB-2019), a protein subunit vaccine candidate for COVID-19 in healthy adults: a phase 1, randomised, double-blind, placebo-controlled trial. Lancet 397, 682–694 (2021).