Does convalescent plasma work as a treatment for COVID-19?

How does it work?

Convalescent plasma is the liquid part of blood (plasma) drawn from people who have recovered (convalesced) from COVID-19. It contains antibodies that help fight the virus off.  Convalescent plasma has been used to treat serious infections for nearly 100 years.

Volunteers who recover from COVID-19 are screened for eligibility to donate. If they are eligible, they give their plasma. It’s very similar to blood donation. The plasma is then given to a sick person.

Figure: Schematic of the use of convalescent plasma for COVID-19.  Reference: Casadevall A, Pirofski LA. The convalescent sera option for containing COVID-19. The Journal of clinical investigation. 2020 Apr 1;130(4):1545-8.

What are the results so far?

Initial experience with convalescent plasma in patients with Covid-19 focused on hospitalized patients who were moderately to severely ill. These studies showed convalescent plasma was safe. However, many high quality randomized controlled trials have been completed now and show no benefit. A study that pooled together data from ten different clinical trials showed convalescent plasma did not decrease death from COVID, did not reduce the length of hospital stays, and did not improve the clinical status of patients.

The FDA originally issued an emergency use authorization on August 23, 2020 and updated that authorization on February 4, 2021. It’s currently authorized only for people who are hospitalized shortly after getting sick. There are ongoing trials to see how well it will work for this patient population.

Last updated: October 20, 2021, at 04:00 ET PM

Update science review: ERS, GSN