SARS-CoV-2 messenger RNA vaccine antibody response and reactogenicity in heart and lung transplant recipients

Abstract

Background: While several studies have observed that solid organ transplant recipients experience diminished antibody responses to SARS-CoV-2 mRNA vaccination, data specific to heart and lung transplant (HT/LT) recipients remains sparse.

Methods: US adult HT and LT recipients completed their vaccine series between January 7 and April 10, 2021. Reactogencity and SARS-CoV-2 anti-spike antibody were assessed after a priming dose (D1) and booster dose (D2). Modified Poisson regression with robust variance estimator was used to evaluate associations between participant characteristics and antibody development.

Results: Of 134 heart recipients, there were 38% non-responders (D1-/D2-), 48% booster responders (D1-/D2+), and 14% priming dose responders (D1+/D2+). Of 103 lung recipients, 64% were non-responders, 27% were booster responders, and 9% were priming dose responders. Lung recipients were less likely to develop antibodies (p < .001). Priming dose antibody response was associated with younger recipient age (p = .04), transplant-to-vaccination time ≥6 years (p < .01), and lack of anti-metabolite maintenance immunosuppression (p < .001). Pain at injection site was the most commonly reported reaction (85% after D1, 76% after D2). Serious reactions were rare, the most common being fatigue (2% after D1 and 3% after D2). No serious adverse events were reported.

Conclusions: HT and LT recipients experienced diminished antibody response following vaccination; reactogenicity was comparable to that of the general population. LT recipients may exhibit a more impaired antibody response than HT recipients. While current recommendations are to vaccinate eligible candidates and recipients, further studies characterizing the cell-mediated immune response and clinical efficacy of these vaccines in this population are needed.

Keywords: COVID-19; SARS-CoV-2; heart transplant; lung transplant; mRNA vaccination.

Figure 1

Semiquantitative SARS-CoV-2 anti-spike antibody immunoassay results of heart and lung transplant recipients by assay type. Individual priming dose responders (Dose 1+) are represented by lines connecting immunoassay results following Dose 1 and Dose 2. Individual booster responders and non-responders (Dose 1-) are represented by points indicating immunoassay results following Dose 2. Antibody-positive cut-offs (determined by the manufacturer and indicated here by thick, horizontal lines) were ≥0.80 U/mL for the anti-RBD immunoassay (Roche Elecsys) and ≥1.1 arbitrary units for the anti-S1 immunoassay (EUROIMMUN). RBD, receptor binding domain. n = 237.

Figure 2

Development of local and systemic adverse events after each SARS-CoV-2 messenger RNA vaccine dose among heart and lung transplant recipients. Percent of participants reporting adverse events within 7 day of receipt of doses 1 and 2 by symptom severity.