Immune Response to SARS-CoV-2 Vaccine among Heart Transplant Recipients: A Systematic Review

Saeed Shoar; Adriana C Carolina Prada-Ruiz; Gabriel Patarroyo-Aponte; Ashok Chaudhary; Mohammad Sadegh Asadi

doi:10.1177/11795484221105327

Immune Response to SARS-CoV-2 Vaccine among Heart Transplant Recipients: A Systematic Review

Clin Med Insights Circ Respir Pulm Med. 2022 Jun 5:16:11795484221105327. doi: 10.1177/11795484221105327. eCollection 2022.

Authors

Saeed Shoar¹, Adriana C Carolina Prada-Ruiz², Gabriel Patarroyo-Aponte³, Ashok Chaudhary⁴, Mohammad Sadegh Asadi⁵

Affiliations

¹ Department of Clinical Research, Scientific Collaborative Initiative, Houston, TX, USA.
² Division of Pediatric Cardiology, Department of Pediatrics, University of Texas Health Science Center at Houston, Houston, TX, USA.
³ Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA.
⁴ Department of Internal Medicine, Griffin Hospital, Derby, CT, USA.
⁵ Division of Cardiology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.

Abstract

Background: Heart transplant (HTX) recipients are at a significantly higher risk of adverse clinical outcomes, due to chronic immunosuppression and co-existence of other chronic conditions, when contracting the SARS-CoV-2 infection. Although vaccination against SARS-CoV-2 is currently the most promising measure for the prevention of severe Coronavirus Disease 2019 (COVID-19) among solid organ transplant recipients, the extent of immune response and its protective efficacy among patients receiving HTX has not been sufficiently studied.

Methods: We performed a systematic review of the literature by inquiring PubMed/Medline to identify original studies among HTX recipients, who had received at least one dose of the SARS-CoV-2 vaccine. Data on the measured humoral or cellular immune response was collected from all the eligible studies. Factors associated with a poor immune response were further investigated within these studies.

Results: A total of 12 studies comprising 563 HTX recipients were included. The average age of the study participants was 60.8 years. Sixty four percent of the study population were male. Ninety percent of the patients had received an mRNA vaccine (Pfizer/ BNT162b2 or Moderna/mRNA-1273). A positive immune response to SARS-CoV-2 vaccine was variably reported in 0% to 100% of the patients. Older age (> 65 years), vaccine dose (first, second, or third), time since HTX to the first dose of the vaccine, the time interval between the latest dose of the vaccine and measurement of the immune response, and the type of immunosuppressive regimen were all indicated as potential determinants of a robust immune response to the SARS-CoV-2 vaccination.

Conclusion: HTX recipients demonstrate a weaker immune response to the vaccination against SARS-CoV-2 compared to the general population. Older age, anti-metabolite agents such as mycophenolate mofetil, and vaccination during the first year following the HTX have been indicated as potential determinants of a poor immune response.

Keywords: COVID-19; SARS-CoV-2 vaccine; cardiac transplantation; cellular immune response; heart transplant; humoral immune response; immunization.

Publication types

Review