Comparative Effectiveness of mRNA-based BNT162b2 Vaccine versus Adenovirus Vector-Based Ad26.COV2.S Vaccine for the Prevention of COVID-19 among Dialysis Patients

Abstract

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.

Keywords: BNT162 vaccine; COVID-19; SARS-CoV-2; comparative effectiveness; dialysis; vaccine.

Figure 1.

Study schema. Eligible patients were those receiving an Ad26.COV2.S shot or a first BNT162b2 shot, who were pair matched on the basis of index date (±1 day), US state, prior COVID-19 status, site of dialysis care (in-center versus home), and propensity score (matched cohort). The primary analytical cohort consisted of matched pairs in which both members remained alive and COVID-19 free through the start of the at-risk period. At-risk time began on the 43^rd day (i.e., the first day after 6 weeks had elapsed) postindex, and continued until the earliest of development of COVID-19, death, or loss to follow-up.

Figure 2.

Kaplan–Meier cumulative incidence curves for COVID-19 during the at-risk period. In each panel, time at-risk is indicated along the x axis. As described in the text, analyses consider only pairs for which both members remained alive and COVID-19-free between index date (date of first shot) and the start of at-risk time (which began on the 43^rd day postindex; vertical dashed line). (A) All matched pairs in the primary analytical cohort (n=2572 pairs); (B) matched pairs from the primary analytical cohort with no prior history of COVID-19 (n=2304 pairs); (C) matched pairs from the primary analytical cohort for which the BNT162b2 member completed the two-dose series (n=2477 pairs); (D) matched pairs from the primary analytical cohort with no history of COVID-19 and in which the BNT162b2 member completed the two-dose series (n=2225 pairs). P values represent the log-rank P value for the difference between Ad26.COV2.S and BNT162b2 groups.

Figure 3.

IRDs for Ad26.COV2.S versus BNT162b2. Rates are presented for all matched pairs in the primary analytical cohort, those pairs with no history of COVID-19 (i.e., preceding index date), completer pairs (pairs for which the patient receiving BNT162b2 completed the two-dose series), and completer pairs with no history of COVID-19. Rates are presented per 1000 pt-weeks at risk. Confidence intervals crossing the null (0, vertical dashed line) indicate no statistically significant difference between Ad26.COV2.S and BNT162b2.