Both SARS and the pathogen which causes COVID-19 are coronaviruses, thought to have come from animals, and so their structures are similar.
The researchers identified eight antibodies that could bind to both COVID-19 and the infected cells.
One candidate, known as S309, was shown to have "particularly strong neutralising activity" against COVID-19.
By combining S309 with other less potent antibodies they were able to target different sites on the virus' protein spike, thus reducing its potential to mutate.
The COVID-19 pandemic has seen hundreds of trials for effective treatment launched, including some involving the use of antibodies from recovered patients.
While there were no experiments on humans in the study, published in the journal Nature, its authors said their findings represent "proof-of-concept" that antibodies from SARS can prevent severe COVID-19 infection and spread.
"These results pave the way for using S309- and S309-containing antibody cocktails for prophylaxis in individuals at high risk of exposure or as a post-exposure therapy to limit or treat severe disease," they wrote.