Highly potent, stable nanobodies stop SARS-CoV-2https://medicalxpress.com/news/2021-07-highly-potent-stable-nanobodies-sars-cov-.htmlAntibodies help our immune system to fend off pathogens. For example, the molecules attach to viruses and neutralize them so that they can no longer infect cells. Antibodies can also be produced industrially and administered to acutely ill patients. They then act like drugs, relieving symptoms and shortening recovery from the disease. This is established practice for treating hepatitis B and rabies. Antibodies are also used for treating COVID-19 patients. However, producing these molecules on an industrial scale is too complex and expensive to meet worldwide demand. Nanobodies could solve this problem.
Scientists at the Max Planck Institute (MPI) for Biophysical Chemistry in Göttingen (Germany) and the University Medical Center Göttingen (UMG) have now developed mini-antibodies (also known as VHH antibodies or nanobodies) that unite all the properties required for a potent drug against COVID-19. "For the first time, they combine extreme stability and outstanding efficacy against the virus and its Alpha, Beta, Gamma, and Delta mutants," emphasizes Dirk Görlich, director at the MPI for Biophysical Chemistry.
At first glance, the new nanobodies hardly differ from anti-SARS-CoV-2 nanobodies developed by other labs. They are all directed against a crucial part of the coronavirus spikes, the receptor-binding domain that the virus deploys for invading host cells. The nanobodies block this binding domain and thereby prevent the virus from infecting cells.
"Our nanobodies can withstand temperatures of up to 95 °C without losing their function or forming aggregates," explains Matthias Dobbelstein, professor and director of the UMG's Institute of Molecular Oncology. "For one thing, this tells us that they might remain active in the body long enough to be effective. For another, heat-resistant nanobodies are easier to produce, process, and store."
Since this treatment is only just entering human testing (or soon will) it's unknown whether there will still be need for a large-quantity SARS-CoV-2 treatment.
However this pioneers not just a new treatment, but also a new treatment technique. One question I have for which I didn't see an answer is how long these nanobodies persist. It sounds like both these nanobody and monoclonal antibody treatments may persist in the recipients' systems for months beyond defeating an infection - more than just a treatment but not as long-lasting as a vaccine.
