Multispecific shark nanobodies for COVID-19

Multi-specific biologics that combine "nanobody" binding domains from nurse shark antibodies — which are smaller and more stable than conventional mAbs because they lack light chains — could protect against COVID-19.

Nurse sharks were immunized with recombinant SARS-CoV-2 S receptor-binding domain (RBD), an RBD-ferritin complex, or spike protein-ferritin nanoparticles, yielding antibodies whose variable regions were fused to human IgG1 Fc domains, and the resulting "ShAb" chimeras were screened for binding to and neutralization of SARS-CoV-2 variants of concern. ...