Humoral and Cellular Immunity following Five Doses of COVID-19 Vaccines in Solid Organ Transplant Recipients: A Systematic Review and Meta-Analysis

• Published in: Vaccines (Basel) 2023-06, Vol.11 (7), p.1166
• Main Authors: Alotaibi, Abdulmalik S, Shalabi, Heba A, Alhifany, Abdullah A, Alotaibi, Nouf E, Alnuhait, Mohammed A, Altheaby, Abdulrahman R, Alhazmi, Abdulfattah Y
• Format: Article
• Language: English
• Subjects: Antibodies; BNT162b2 (BioNTech/Pfizer); Cell-mediated immunity; Clinical trials; Corticoids; Corticosteroids; COVID-19 vaccine; COVID-19 vaccines; Dialysis; Health aspects; Health risks; humoral and cellular immunity; Humoral immunity; Immunocompromised hosts; Immunogenicity; immunosuppressed patients; Immunosuppressive agents; kidney transplant; Lymphocytes; Medical research; Meta-analysis; Mycophenolate mofetil; Mycophenolic acid; Observational studies; Organ transplant recipients; Risk factors; Severe acute respiratory syndrome coronavirus 2; solid organ transplant; Systematic Review; Testing; Transplants & implants; Vaccines; Viral antibodies
• ISSN: 2076-393X; 2076-393X
• DOI: 10.3390/vaccines11071166

Solid organ transplant (SOT) recipients are at increased risk of COVID-19 infection because of their suppressed immunity. The available data show that COVID-19 vaccines are less effective in SOT recipients. We aimed to assess the cellular and humoral immunogenicity with an increasing the number of doses of COVID-19 vaccines in SOT recipients and to identify factors affecting vaccine response in this population. A systematic review and meta-analysis were conducted to identify ongoing and completed studies of humoral and cellular immunity following COVID-19 vaccines in SOT recipients. The search retrieved 278 results with 45 duplicates, and 43 records did not match the inclusion criteria. After title and abstract screening, we retained 189 records, and 135 records were excluded. The reasons for exclusion involved studies with immunocompromised patients (non-transplant recipients), dialysis patients, and individuals who had already recovered from SARS-CoV-2 infection. After full-text reading, 55 observational studies and randomized clinical trials (RCTs) were included. The proportion of responders appeared higher after the third, fourth, and fifth doses. The risk factors for non-response included older age and the use of mycophenolate mofetil, corticosteroids, and other immunosuppressants. This systematic review and meta-analysis demonstrates the immunogenicity following different doses of COVID-19 vaccines among SOT patients. Due to the low immunogenicity of vaccines, additional strategies to improve vaccine response may be necessary.