Clin J Am Soc Nephrol. 2023 Oct 17. doi: 10.2215/CJN.0000000000000328. Online ahead of print.
BACKGROUND: There is a lack of randomized controlled trial data regarding differences in immunogenicity of varying COVID-19 mRNA vaccine regimens in chronic kidney disease (CKD) populations.
METHODS: We conducted a randomized controlled trial at three kidney centres in Toronto, Ontario, Canada evaluating the SARS-CoV-2 antibody response following third dose vaccination. Participants (n=273) with CKD not on dialysis or receiving dialysis were randomized 1:1 to third dose 30µg BNT162b2 (Pfizer-BioNTech) or 100µg mRNA-1273 (Moderna). The primary outcome of this study was SARS-CoV-2 IgG binding antibodies to the receptor binding domain (anti-RBD). Spike protein (anti-spike), nucleocapsid protein, and vaccine reactogenicity were also evaluated. Serology was measured prior to third dose, 1 month, 3 months, and 6 months following third dose. A subset of participants (n=100) were randomly selected to assess viral pseudovirus neutralization against wild-type D614G, B.1.617.2 (Delta), and B.1.1.529 (Omicron BA.1).
RESULTS: Among 273 participants randomized, 94% were receiving maintenance dialysis and 59% received BNT162b2 for initial two dose COVID-19 vaccination. Third dose of mRNA-1273 was associated with higher mean anti-RBD levels (1871 BAU/mL; 95% CI 829, 2988) over a 6-month period in comparison to third dose BNT162b2 (1332 BAU/mL; 95% CI 367, 2402) with a difference of 539 BAU/mL (95% CI 139, 910; p=0.009). Neither anti-spike levels nor neutralizing antibodies to wild-type, Delta, Omicron BA.1 pseudoviruses were statistically different. COVID-19 infection occurred in 10% of participants:15 (11%) receiving mRNA-1273 and 11 (8%) receiving BNT162b2. Third dose BNT162b2 was not associated with a significant different risk for COVID-19 in comparison to mRNA-1273 (HR 0.78; 95% CI 0.27, 2.2, p=0.63).
CONCLUSIONS: In patients with CKD third dose COVID-19 mRNA vaccination with mRNA-1273 elicited higher SARS-CoV-2 anti-RBD levels in comparison to BNT162b2 over a 6-month period.