Amid the growing threat of a new and potentially more dangerous SARS-CoV-2 variant, scientists are ramping up the quest for COVID treatments. A recent study demonstrates the therapeutic potential of an unusual class of immune proteins: miniature antibodies called nanobodies, derived from llamas. Rockefeller University scientists Michael P. Rout, PhD, and Brian T. Chait, PhD, and their colleagues at the Seattle Children’s Research Institute selected a repertoire of over one hundred nanobodies based on their potency and ability to target different parts of the SARS-CoV-2 spike protein. Produced by immunized llamas, the nanobodies were shown to neutralize the original coronavirus and several of its variants, including Delta, with high efficacy in lab tests. Studies to assess their potency against the new Omicron variant are underway.