Real-world Effectiveness of the Pfizer-BioNTech BNT162b2 and Oxford-AstraZeneca ChAdOx1-S Vaccines Against SARS-CoV-2 in Solid Organ and Islet Transplant Recipients

Abstract

Background. The clinical effectiveness of vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in immunosuppressed solid organ and islet transplant (SOT) recipients is unclear. Methods. We linked 4 national registries to retrospectively identify laboratory-confirmed SARS-CoV-2 infections and deaths within 28 d in England between September 1, 2020, and August 31, 2021, comparing unvaccinated adult SOT recipients and those who had received 2 doses of ChAdOx1-S or BNT162b2 vaccine. Infection incidence rate ratios were adjusted for recipient demographics and calendar month using a negative binomial regression model, with 95% confidence intervals. Case fatality rate ratios were adjusted using a Cox proportional hazards model to generate hazard ratio (95% confidence interval). Results. On August 31, 2021, it was found that 3080 (7.1%) were unvaccinated, 1141 (2.6%) had 1 vaccine dose, and 39 260 (90.3%) had 2 vaccine doses. There were 4147 SARS-CoV-2 infections and 407 deaths (unadjusted case fatality rate 9.8%). The riskadjusted infection incidence rate ratio was 1.29 (1.03-1.61), implying that vaccination was not associated with reduction in risk of testing positive for SARS-CoV-2 RNA. Overall, the hazard ratio for death within 28 d of SARS-CoV-2 infection was 0.80 (0.63-1.00), a 20% reduction in risk of death in vaccinated patients (P = 0.05). Two doses of ChAdOx1-S were associated with a significantly reduced risk of death (hazard ratio, 0.69; 0.52-0.92), whereas vaccination with BNT162b2 was not (0.97; 0.71-1.31). Conclusions. Vaccination of SOT recipients confers some protection against SARS-CoV-2-related mortality, but this protection is inferior to that achieved in the general population. SOT recipients require additional protective measures, including further vaccine doses, antiviral drugs, and nonpharmaceutical interventions. (Transplantation 2022;106: 436-446).

COVID-19 and kidney disease: insights from epidemiology to inform clinical practice

“…A more recent study found that a third dose of BNT162b2 Pfizer vaccine improved humoral immune responses in kidney transplant recipients 137 ; however, the effectiveness of this approach on clinical outcomes such as death and hospitalization remains unknown. An analysis of national transplant registry data from England found that while fewer deaths occurred among transplant recipients vaccinated with the ChAdOx1-S Oxford–AstraZeneca vaccine than among unvaccinated transplant recipients following SARS-CoV-2 infection, there was no survival benefit associated with the BNT162b2 Pfizer vaccine 138 . However, this apparent lack of benefit from the BNT162b2 Pfizer vaccine might have been due to the result of residual confounding due to comorbidities or age (which was classified, somewhat crudely, as 16–49 or >50 years) if those considered higher risk were more likely to receive BNT162b2 Pfizer in the earliest stages of the vaccine rollout.…”

Monoclonal Antibody Therapy in Kidney Transplant Recipients With Delta and Omicron Variants of SARS-CoV-2: A Single-Center Case Series

“… 8 Moreover, the clinical benefit of vaccine to protect against severe COVID-19 has appeared lower in solid organ transplant recipients compared to the general population. 9 …”

SARS‐CoV‐2 vaccine clinical efficacy in SOT: What we know and our current gaps

“…T‐cell response ranges from 5–79% in various studies and may be present despite lack of measurable antibody 6,8,9 . Only a few studies have assessed clinical outcomes and demonstrate reduced rate of symptomatic COVID‐19 and reduced mortality 10–12 . In one single center study, there was an almost 80% reduction in risk of symptomatic COVID‐19 compared to unvaccinated SOTR 12 .…”