Vaccine-boosted convalescent plasma therapy for patients with immunosuppression and COVID-19

In this case series, Mayo Clinic researchers highlight a retrospective single-center study that was conducted at Mayo Clinic (Rochester, Minnesota) examining COVID-19 convalescent plasma collected from persons who had been both naturally infected with SARS-CoV-2 and vaccinated against SARS-CoV-2 (i.e., “vax-plasma”). Thirty-one consecutive patients treated with vax-plasma were included in the study, which ran from July 1, 2021 to September 1, 2022. Patient follow-up was continued until death or most recent follow-up and the median follow-up time was 176 days.

Highlights of the case study:

  • Eligible vax-plasma donors included individuals who had a polymerase chain reaction (PCR)-confirmed diagnosis of COVID-19 and had received at least one dose of a SARS-CoV-2 vaccine.
  • Immunocompromised patients with active COVID-19 infection, confirmed by SARS-CoV-2-specific reverse transcription PCR, were eligible to receive vax-plasma.
  • Antibody titers of vax-plasma units met the minimum threshold required by US FDA for high titer anti-SARS-CoV-2 antibodies, but precise antibody titers were not evaluated.
  • Twenty-one patients were treated for hematologic malignancies, six patients were treated for rheumatic diseases, three patients had received a solid organ transplant, one patient was treated for multiple sclerosis, one patient was treated for a brain tumor, and one patient was diagnosed with common variable immune deficiency during COVID-19 disease.
  • In line with previous findings and the biological principles of antibody therapy, the benefit of vax-plasma was most apparent in patients who were treated before disease progression to invasive mechanical ventilation.
  • Despite the enumerated limitations of this study, the data suggest that transfusion of vax plasma is safe and effectively transfers COVID-19-neutralizing antibodies to patients with immunosuppression and protracted COVID-19.