O’FALLON, Mo. (AP) — A blood bank operating in Missouri and three other Midwestern states is seeking plasma donations from people who have recovered from the coronavirus in hopes of helping those still battling the disease. A spokesman for the Mississippi Valley Regional Blood Center said Friday that the blood bank is seeking people who tested positive and have not had symptoms for at least 28 days.

The blood bank operates in parts of Missouri, Illinois, Iowa and Wisconsin. The therapy was used during the 1918 flu pandemic, and has been used in recent years to treat victims of Ebola, SARS and the H1N1 virus.