The thermal and chemical stability of single-domain antibodies position them as a potential therapy for viral infections. Could this approach be applied in COVID-19?
SARS-CoV, MERS-CoV and SARS-CoV-2 are zoonotic pathogens. SARS-CoV spike protein-directed single-domain antibodies cross-react with SARS-CoV-2 and MERS-CoV. In recent research, immunization of llamas with perfusion-stabilized spike-proteins of betacoronavirus induced bivalent cross-reactive single-domain camelid antibodies that could neutralize SARS-CoV-2 pseudoviruses. Crystallography has revealed that single-domain antibodies impede viral penetration into cells. The favorable biophysical and potent neutralization properties support the possibility of therapeutic use.205 Human monoclonal antibodies may offer similar neutralization capacity with potential for better tolerability and a longer half-life.206