Convalescent plasma is created from the blood of people who have recovered from the novel coronavirus COVID-19.
CNN reports convalescent plasma already shown some success in two other deadly coronaviruses: MERS and SARS.
However, like blood, convalescent plasma is in limited supply and must come from donors.
And while there are promising signals from some studies, there is not yet any randomized clinical trial data on convalescent plasma to treat COVID-19.
Sources say a White House briefing Sunday is expected to be about an emergency use authorization for the use of convalescent plasma to treat COVID-19.
Last week, President Trump accused some health officials of playing politics regarding an EUA for convalescent plasma.