Shares of Eli Lilly & Co. /zigman2/quotes/200106384/composite LLY +2.19% were down 1.6% in trading on Friday after the company said the Food and Drug Administration has extended the emergency authorization for its COVID-19 antibody therapy to include children younger than 12 years old. This is the first authorization for a monoclonal antibody treatment for infants and children. Lilly said the therapy can now be used in high-risk children as a treatment or for post-exposure prophylaxis. The company also said that more than 700,000 patients have been treated with bamlanivimab or a combination of bamlanivimab and etesevimab. Lilly's stock is up 44.5% so far this year, while the broader S&P 500 /zigman2/quotes/210599714/realtime SPX +1.64% has gained 21.6%.