The neutralizing effects identified suggest infections in humans can be blocked. Additionally, the effects were equal to or better than those found in antibody candidates derived from patients who had recovered from COVID-19, according to data collected from in vitro studies conducted by Saint Louis University and independently verified by scientists at Colorado State University.

The studies involved testing more than 200 monoclonal and VHH antibodies against live virus and pseudovirus cells. Each antibody was chosen for its high and unbiased binding affinity to either the receptor binding domain of the S1 protein of SARS-CoV-2 or the extracellular domain of angiotensin I converting enzyme 2 (ACE2) in human cells.

Currently, the antibodies moving through clinical development for the treatment of COVID-19 are IgG antibodies, many of which show promise. The VHH antibodies included in these assays may represent a different path to treating the disease. Since the nanobodies are much smaller than IgG antibodies, they may be able to access epitopes on the virus that IgGs can't.