Abstract
The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in over 100 million infections and millions of deaths. Effective vaccines remain the best hope of curtailing SARS-CoV-2 transmission, morbidity, and mortality. The vaccines in current use require cold storage and sophisticated manufacturing capacity, which complicates their distribution, especially in less developed countries. We report the development of a candidate SARS-CoV-2 vaccine that is purely protein based and directly targets antigen-presenting cells. It consists of the SARS-CoV-2 Spike receptor-binding domain (SpikeRBD) fused to an alpaca-derived nanobody that recognizes class II major histocompatibility complex antigens (VHHMHCII). This vaccine elicits robust humoral and cellular immunity against SARS-CoV-2 and its variants. Both young and aged mice immunized with two doses of VHHMHCII-SpikeRBD elicit high-titer binding and neutralizing antibodies. Immunization also induces strong cellular immunity, including a robust CD8 T cell response. VHHMHCII-SpikeRBD is stable for at least 7 d at room temperature and can be lyophilized without loss of efficacy.
Original language | English |
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Article number | e2116147118 |
Pages (from-to) | 1-10 |
Journal | Proceedings of the National Academy of Sciences of the United States of America |
Volume | 118 |
Issue number | 44 |
DOIs | |
Publication status | Published - 2 Nov 2021 |
Keywords
- Amino Acid Sequence
- Animals
- Antibodies, Neutralizing/biosynthesis
- Antibodies, Viral/biosynthesis
- Antigen-Presenting Cells/immunology
- CD8-Positive T-Lymphocytes/immunology
- COVID-19 Vaccines/administration & dosage
- COVID-19/epidemiology
- Camelids, New World/immunology
- Female
- Histocompatibility Antigens Class II/immunology
- Humans
- Immunity, Cellular
- Immunity, Humoral
- Immunization, Secondary
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Transgenic
- Pandemics/prevention & control
- Recombinant Fusion Proteins/administration & dosage
- SARS-CoV-2/genetics
- Single-Domain Antibodies/administration & dosage
- Spike Glycoprotein, Coronavirus/administration & dosage
- COVID-19
- Nanobody
- Vaccine