Shares of Eli Lilly & Co. gained 1.1% in premarket trading on Monday after the drugmaker said it started a Phase 3 trial for a treatment that aims to prevent COVID-19 infections in residents and workers in nursing homes. It is estimated that at least 8% of U.S. COVID-19 cases and more than 41% of deaths have occurred in people linked to nursing homes, according to The New York Times. Lilly is testing an experimental antibody it developed with the privately held AbCellera Biologics Inc. to see if it can prevent infections in people who live or work in a facility that has recently reported a case of the coronavirus. The antibody was identified in the blood sample of one of the first people in the U.S. to test positive for the virus. The trial, expected to enroll 2,400 people by September, will be conducted with the National Institute of Allergy and Infectious Diseases, with plans to release the late-stage data sometime in the fourth quarter. Lilly’s stock has gained 14.3% so far this year. The S&P 500 is up 1.2%. Market Pulse Stories are Rapid-fire, short news bursts on stocks and markets as they move. Visit MarketWatch.com for more information on this news.