Göttingen researchers have developed mini-antibodies that efficiently block the coronavirus SARS-CoV-2 and its dangerous new variants. These so-called nanobodies bind and neutralize the virus up to 1,000 times better than previously developed mini-antibodies. In addition, the scientists optimized their mini-antibodies for stability and resistance to extreme heat. This unique combination makes them promising agents to treat COVID-19. Since nanobodies can be produced at low costs in large quantities, they could meet the global demand for COVID-19 therapeutics. The new nanobodies are currently in preparation for clinical trials.