This is a summary, written by members of the CITF Secretariat, of:

Yau K, Tam P, Chan CT, Hu Q, Qi F, Abe KT, Kurtesi A, Jiang Y, Estrada-Codecido J, Brown T, Liu L, Siwakoti A, Leis JA, Levin A, Oliver MJ, Colwill K, Gingras AC, Hladunewich MA. BNT162b2 versus mRNA-1273 Third Dose COVID-19 Vaccine in Patients with CKD and Maintenance Dialysis Patients. Clin J Am Soc Nephrol. 2023 Oct 17. doi: 10.2215/CJN.0000000000000328.

The results and/or conclusions contained in the research do not necessarily reflect the views of all CITF members.

A CITF-funded study, published in the Clinical Journal of the American Society of Nephrology, showed that a third dose of COVID-19 mRNA vaccine with  Moderna (monovalent) given to patients with chronic kidney disease (CKD) elicited higher SARS-CoV-2 anti-RBD levels than with the Pfizer (monovalent) vaccine over a six-month period. The study was led by Dr. Michelle A. Hladunewich (University of Toronto) in collaboration with Drs. Anne-Claude Gingras (Lunenfeld-Tanenbaum Research Institute at Mount Sinai Hospital) and Matthew J Oliver (University of Toronto).

Key findings:

  • The third dose of Moderna mRNA-1273 was associated with higher mean anti-RBD levels (1871 BAU/mL) over a six-month period in comparison to the third dose of Pfizer BNT162b2 (1332 BAU/mL), with a difference of 539 BAU/mL.
  • There were no statistical differences in anti-spike levels or neutralizing antibodies to wild-type, Delta, Omicron BA.1 pseudoviruses elicited by the two vaccines. However, participants who received a third dose of Moderna mRNA-1273 had higher anti-spike and overall neutralizing antibodies. Individuals with heterologous mRNA vaccine regimens had antibody levels that were intermediate in amplitude compared to the homologous regimens, i.e., between Moderna/Moderna/Moderna and Pfizer/Pfizer/Pfizer.
  • The risk of getting infected with SARS-CoV-2 was not significantly different whether the person had had a third dose of Pfizer BNT162b2 or mRNA-1273. SARS-CoV-2 infection occurred in 10% (n=26) of participants: 15 receiving Moderna mRNA-1273 and 11 receiving Pfizer BNT162b2. No serious adverse events related to vaccination were reported. Both vaccines were generally well tolerated among study participants.

This randomized controlled trial was conducted at three kidney centres in Toronto to evaluate the SARS-CoV-2 antibody response following third dose vaccination. Participants (n=273) with CKD receiving dialysis (94%) or not on dialysis (6%) were randomized 1:1 to a third dose of 30µg BNT162b2 (Pfizer-BioNTech) or 100µg mRNA-1273 (Moderna). All participants were ≥18 years old. Patients who received heterologous vaccination for the first two doses of vaccine and those with a severe allergic reaction to COVID-19 vaccination were excluded.

Overall, participants had a median age of 67 years; 44% were female, 3% had prior COVID-19, and 59% had received Pfizer for their initial two doses. Among those who received Pfizer for their first two doses, 50% were allocated a third dose of Moderna and 50% a third dose of Pfizer. 64% of participants received a fourth dose as part of routine clinical care and were censored for further analysis.