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