Rare, super coronavirus antibodies likely to yield vaccine, say Stanford, UCSF experts: The discovery of antibodies that block the most infectious elements of the coronavirus is helping Bay Area scientists unlock the many mysteries of human immunity, and could be crucial in the development of a vaccine. Epidemiologists have found “neutralizing antibodies” in fewer than 5% of COVID-19 patients, but the ones they are now attempting to isolate are unique in their ability to prevent SARS-CoV-2 — the specific coronavirus that causes the illness — from entering human cells.