Llamas and other camelids fight off pathogens like viruses with tiny antibodies called single-domain antibodies or "nanobodies." The UCSF team used protein engineering to make a synthetic nanobody that prevents the spike protein on the surface of SARS-CoV-2, the virus that causes COVID-19, from binding to healthy cells and infecting them.In tests against the live virus in the lab, an aerosolized form of the nanobody rendered SARS-CoV-2 incapable of binding to the ACE2 receptor on healthy cells that line airways. The synthetic nanobody remained functional after it was freeze-dried, exposed to heat and aerosolized, they reported (PDF) in the preprint journal bioRxiv . The UCSF team dubbed the aerosol formulation "AeroNabs."
UCSF’s Walter said the llama-inspired AeroNabs could be used as a sort of personal protective equipment, a "stopgap" until the vaccines become available. UCSF is planning human trials and is in discussions with partners who could provide manufacturing and distribution support.