“…This structure can retain the antibody's antigen-binding specificity, but it will often reduce its affinity and solubility. Due to the emergence of recombinant DNA technology many antibody domains and fragments have been developed as attractive alternatives to conventional antibodies [ [9] , [10] , [11] , [12] , [13] , [14] ]. Due to their small size, superior properties and ease of manufacturing they became excellent candidates for the development of antibodies against COVID-19.…”