Immunity Against SARS-CoV-2 Can Be Transferred From Stem-Cell Donor to Recipient

NEW YORK (Reuters Health) – B-cell-mediated immunity against SARS-CoV-2 can be transferred from a hematopoietic stem-cell transplant (HSCT) donor to a recipient, according to a small single-center study from France.

Dr. Sebastien Maury and colleagues with Henri Mondor Hospital, in Creteil, studied 14 patients who received the Pfizer mRNA vaccine before HSCT, including 11 who received their HSCT from a vaccinated donor and three who were transplanted from non-vaccinated donors.

Pre-HSCT vaccination of donors significantly boosted early post-HSCT immune response to the vaccine, and in the midst of ongoing immunosuppressive therapy, the researchers report in The Lancet Haematology.

“The present study adds to previous demonstrations of the adoptive transfer of an immune memory against an infectious agent from the donor to the recipient in the setting of HSCT,” they write.

“The impact of donor natural immunization against pathogens is well demonstrated for the cytomegalovirus (CMV), with recipients transplanted from a seropositive donor (when they are seropositive themselves) having an overall survival benefit related to protection against CMV re-activation as compared with those receiving their HSCT from a naive donor against CMV. Thus, donor CMV serological status is a key factor in the algorithm of donor choice,” Dr. Maury and colleagues point out.

Although the findings in this small study need to be replicated, they “provide a rationale for incorporating donor serological status against SARS-CoV-2 into the algorithm of donor choice, or inciting donor vaccination before donation, if feasible,” the researchers say.

In addition, they suggest “early and efficient” vaccination or re-vaccination of every HSCT recipient “should be a priority, starting at three months post-HSCT.”

The authors have no relevant disclosures.

SOURCE: The Lancet Haematology, online April 1, 2022.

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