In May 2020, a research group consisting of researchers from The Kitasato Institute, Epsilon Molecular Engineering, Inc., and Kao Corporation announced that they had discovered VHH antibodies that neutralize severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
The group was then joined by researchers from the Department of Organoid Medicine, Sakaguchi Laboratory, Keio University School of Medicine, the Department of Pulmonary Medicine, Keio University School of Medicine, and the National Institute for Physiological Sciences, National Institutes of Natural Sciences. A subsequent study showed that nasal delivery of VHH antibodies inhibited replication of SARS-CoV-2 in infected lungs of hamster models. This effect was also demonstrated in an experiment using human lung–derived alveolar organoids, also called micro-organs. In addition, their analysis using cryoelectron microscopy revealed the binding pattern between SARS-CoV-2 spike proteins and VHH antibodies.
These results showed that the aforementioned VHH antibodies are a potential therapeutic agent for coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2. The results also suggested the possibility of nasal delivery of drugs for the treatment of COVID-19, which is a new administration route for COVID-19 treatment that may expand the available treatment options for COVID-19.
These findings were reported in the American scientific journal PLOS Pathogens (https://doi.org/10.1371/journal.ppat.1009542).
