Determining the Safety and Efficacy of COVID-19 Vaccination in the Chronic Kidney Disease Population [CKD-COVID19, study data contributed to the CITF Databank]

Aims of the CITF-funded study: The goals of the cohort study were to determine COVID-19 vaccine effectiveness in the dialysis population and to evaluate the safety and serological response to the COVID-19 vaccine and booster shots in patients with CKD. The randomized controlled clinical trial aimed to determine the effect of the third dose of Moderna or Pfizer COVID-19 vaccine on the humoral immune response of CKD and hemodialysis patients, and to measure antibody levels and adverse events following the third dose.

Methods

The cohort study recruited prevalent maintenance dialysis patients (those who received the Oxford-AstraZeneca vaccine, tested positive for COVID-19 within 14 days of study entry, or were receiving acute dialysis were excluded), patients diagnosed with CKD stage 3b, 4, or 5 , and healthcare workers in “generally good health” from clinics in Ontario and British Columbia. Information was collected from the dialysis population from administrative databases (Ontario Renal Reporting System (ORRS) and Patient Record and Outcomes Management Information System) at baseline, prior to vaccination, and after the first and second doses of the COVID-19 vaccine.

For the CKD population, administrative information was collected at baseline and at various follow ups following the first, second, and third doses of the COVID-19 vaccine. Participants provided blood samples at all visits, including baseline, except for at follow ups 1-week post-dose, where they answered questionnaires instead. Similarly, the healthcare workers provided blood samples and administrative information was collected at all visits, including baseline, except for visits 1-week post-dose, where questionnaires were answered instead.

The randomized controlled clinical trial population was composed of 4 groups of patients with CKD stage 3b, 4, or 5, from Ontario. Group 1 received all three doses of Pfizer-BioNTech COVID-19 vaccine, Group 2 received the two doses of MODERNA COVID-19 vaccine and a third dose from Pfizer-BioNTech, Group 3 received two doses of Pfizer-BioNTech and a third dose from MODERNA, and Group 4 received all three doses from MODERNA.

All groups provided a blood sample and information from the ORRS at follow ups prior to each dose and, 1, 3, 6,9, and 12 months after the third dose. 48 hours to 14 days after dose 3, participants completed a questionnaire relating to adverse events instead. Contributed dataset contents: The datasets include 2377 participants with baseline information, 292 from the randomized controlled clinical trial, and 2085 from the observational cohort study (1016 from Ontario and 1069 from British Columbia).

Within the Boost RCT, 259 participants had dialysis CKD and 16 had non-dialysis CKD. Within the observational data, there were 709 participants with non-dialysis CKD, 1111 with dialysis CKD, and, in the Ontario data, 110 healthy controls. Kidney disease status was determined at baseline or enrollment for these participants; remaining participants had no reported status.

About 87% of participants gave one or more blood samples between February 2021 and December 2023 for analysis. A total of 9198 samples were collected. Variables include data in the following areas of information: demographics (age, sex, race-ethnicity), general health (smokes, chronic conditions, height and weight), CKD characteristics, longitudinal follow-up for COVID infections (dates of positive PCR or RAT tests, hospitalization, symptoms), SARS-CoV-2 vaccination, and serology (antibodies against SARS-CoV-2 RBD, nucleocapsid, and spike proteins).