(Reuters) - Regeneron Pharmaceuticals Inc said on Tuesday its antibody cocktail was found effective in preventing COVID-19 in people exposed to those infected with the new coronavirus in an ongoing late stage trial. The two-antibody cocktail, REGEN-COV, caused a 100% reduction in symptomatic infection and roughly 50% lower overall rates of infection, based on an early analysis of 400 participants in the trial who had a household member with COVID-19. In comparison, rival Eli Lilly and Co said last week its antibody drug, bamlanivimab, cut the risk of COVID-19 infection by 80% for nursing home residents in a trial. Regeneron said it would discuss the interim results with U.S. health regulators to potentially expand the antibody cocktail’s current emergency use authorization (EUA). Full data from the trial is expected early in the second quarter. The U.S. Food and Drug Administration in November granted EUA to the antibody cocktail for the treatment of mild to moderate COVID-19 in adults and children. The current trial tested REGEN-COV for use as a passive vaccine, which involves direct delivery of virus-fighting antibodies into the body unlike traditional vaccines in which the receiver’s immune system is activated to develop its own antibodies. “These data using REGEN-COV as a passive vaccine suggest that it may both reduce transmission of the virus as well as reduce viral and disease burden in those who still get infected,” said George Yancopoulos, president and chief scientific officer of Regeneron. During the trial, jointly run by Regeneron and the National Institute of Allergy and Infectious Diseases, one death and a COVID-19 related hospitalization were reported among those who received placebo, but there was no such incident in the treatment group, the company said.