(WTTW News via CNN)

Nine months into the pandemic, many health care workers say they’re reaching a breaking point, and they’re bracing for what health officials say could be one of the most difficult winters in American public health history.  

 In this Friday, June 12, 2020 file photo, a doctor holds a bag of blood plasma donated by a COVID-19 survivor at a blood bank in La Paz, Bolivia. (AP Photo / Juan Karita)

A group of medical experts advising the National Institutes of Health says there is not enough evidence to recommend for or against the use of plasma therapy for patients hospitalized with COVID-19.