Physicians at Orlando Health have used convalescent plasma transplants in 12 patients and are seeing “drastic improvements” in at least two of those patients, Dr. Sunil Desai said in a press conference Sunday afternoon with Florida Gov. Ron DeSantis.

The process, known as plasma-derived therapy or convalescent plasma, involves doctors testing the plasma of people who recovered for antibodies to the virus and then injecting that plasma, or a derivative of it, into a sick person.

Plasma from recovered Covid-19 patients have been given to 12 patients in the health system, Desai said, and he has direct knowledge of two patients showing drastic improvements.

Physicians are asking every patient who has tested positive to donate plasma, Desai said.

The hospital began doing the convalescent plasma transplants two weeks ago to help treat Covid-19.

Orlando Health officials said that cases in their area peaked April 1. Their hospitalization peak was at 116 patients on April 7. They currently have 68.