In the continuing hunt for antibodies that could fight the novel coronavirus SARS-CoV-2, researchers have mostly looked at people who have already contracted Covid-19. There have been at least two exceptions, both of which have looked at antibodies developed by survivors of another outbreak, SARS, 17 years ago.One antibody, called S309, taken from a SARS survivor from 2003, has been shown in the lab to neutralize SARS-CoV-2. The results were reported in Nature this week.The other antibody, called CR3022, was first isolated in 2006, again from a SARS survivor of the early 2000s. CR3022 may hold clues to the vulnerability of SARS-CoV-2, researchers reported in Science last month.