Comparative Effectiveness of mRNA-based BNT162b2 Vaccine versus Adenovirus Vector–Based Ad26.COV2.S Vaccine for the Prevention of COVID-19 among Dialysis Patients
Authors: Brunelli Steven M. , Sibbel Scott , Karpinski Steph , Marlowe Gilbert , Walker Adam G. , Giullian Jeffrey , Van Wyck David , Kelley Tara , Lazar Rachael , Zywno Meredith L. , Connaire Jeffrey J. , Young Amy , Tentori Francesca 
Published: February 2022

Significance Statement
Vaccination against SARS-CoV-2 is critically important for patients on maintenance dialysis, who are at high risk for COVID-19–related morbidity and mortality. Previous research has demonstrated that mRNA-based vaccines are highly effective in patients on dialysis. Because specific vaccines may be differentially available to patients, it is important to understand the comparative effectiveness of individual vaccines, including the adenovirus vector–based vaccine Ad26.COV2.S. In this retrospective study, the authors compared the real-world effectiveness of Ad26.COV2.S with that of an mRNA vaccine, BNT162b2, in a population of patients on dialysis. Their findings showed no difference in the effectiveness of these vaccines over the first 6 months postvaccination, and support the continued use of either in the population of patients on dialysis.

Background
Studies have demonstrated that mRNA-based SARS-CoV-2 vaccines are highly effective among patients on dialysis. Because individual vaccines may be differentially available or acceptable to patients, it is important to understand comparative effectiveness relative to other vaccines, such those on the basis of adenovirus technologies.

Methods
In this retrospective study, we compared the clinical effectiveness of adenovirus vector–based Ad26.COV2.S (Janssen/Johnson & Johnson) to mRNA-based BNT162b2 (Pfizer/BioNTech) in a contemporary cohort of patients on dialysis. Patients who received a first BNT162b2 dose were matched 1:1 to Ad26.COV2.S recipients on the basis of date of first vaccine receipt, US state of residence, site of dialysis care (in-center versus home), history of COVID-19, and propensity score. The primary outcome was the comparative rate of COVID-19 diagnoses starting in the 7th week postvaccination. In a subset of consented patients who received Ad26.COV2.S, blood samples were collected ≥28 days after vaccination and anti–SARS-CoV-2 immunoglobulin G antibodies were measured.

Results
A total of 2572 matched pairs of patients qualified for analysis. Cumulative incidence rates of COVID-19 did not differ for BNT162b2 versus Ad26.COV2.S. No differences were observed in peri–COVID-19 hospitalizations and deaths among patients receiving BNT162b2 versus Ad26.COV2.S, who were diagnosed with COVID-19 during the at-risk period. Results were similar when excluding patients with a history of COVID-19, in subgroup analyses restricted to patients who completed the two-dose BNT162b2 regimen, and in patients receiving in-center hemodialysis. SARS-CoV-2 antibodies were detected in 59.4% of 244 patients who received Ad26.COV2.S.

Conclusions
In a large real-world cohort of patients on dialysis, no difference was detected in clinical effectiveness of BNT162b2 and Ad26.COV2.S over the first 6 months postvaccination, despite an inconsistent antibody response to the latter.