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

Atiquzzaman M, Zheng Y, Er L, Djurdjev O, Singer J, Krajden M, Balamchi S, Thomas D, Oliver MJ, Levin A. COVID-19 vaccine effectiveness in patients with non-dialysis dependent chronic kidney diseases; findings from a population-based observational study from British Columbia, Canada. Kidney international. 2022 Sep 11. https://doi.org/10.1016/j.kint.2022.08.027.

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

A research letter by CITF-funded Drs. Mel Krajden (BC Centre for Disease Control), Matthew Oliver (University of Toronto), and Adeera Levin (University of British Columbia), published in Kidney International, investigated the effectiveness of COVID-19 vaccines among non-dialysis dependent patients with chronic kidney disease (CKD). Even though these individuals produce lower antibody titers and a less sustained humoral response that might result in lower protection after vaccination, the researchers found that 2 or 3 doses of COVID-19 vaccines were highly effective in preventing incident COVID-19 infection (≥71%) as well as COVID-19-related hospitalization and death (≥84%) between December 2020 and December 2021.

Key findings:

  • Compared to pre-vaccination person-timePerson-time is an estimate of the actual time-at-risk – in years, months, or days – that all participants contributed to a study., the risk of developing COVID-19 infection was 59%, 71% and 78% less among CKD patients who received 1, 2, or 3 vaccine doses, respectively.
  • Compared to pre-vaccination person-time, the risk of COVID-19-related hospitalization or death was 53%, 84% and 90% less among CKD patients vaccinated with 1 dose, 2 doses and 3 doses, respectively.
  • For exposure to 3 doses, the risk of COVID-19 was 83% less in patients with eGFR <30 ml/min/1.73m2 compared to 73% decreased risk in patients with eGFReGFR – Estimated Glomerular Filtration Rate is a measure of how well the kidneys are working. In adults, the normal eGFR number is more than 90. eGFR declines with age, even in people without kidney disease. ≥30 ml/min/1.73m2.
  • Vaccine effectiveness (VE) was similar across age, sex, presence of comorbidities, and baseline history of immunosuppressive medication use.

The study sample included 18,850 CKD patients followed by nephrologists in BC. Non-dialysis dependent CKD patients aged at least 18 years who were actively registered in PROMISPROMIS – the Patient Records and Outcome Management Information System – is the province-wide integrated registry and clinical information system for kidney disease and transplant patients. as of December 14, 2020 (prevalent patients) and those newly entered between December 15, 2020, and December 31, 2021 (incident patients) were included in the study cohort.

The median age of the participants was 74 years, and 53% were male. The Median follow-up time was 382 days. By the end of follow-up, half of the study sample had received their third dose, and a substantial proportion (33%) received two doses. Only 797 (4%) received one dose, and 2,418 (13%) patients did not receive any vaccine.

The VE observed in this study are most likely against the Alpha and Delta variants, pre-Omicron, given the time period sampled. The researchers anticipated that 3% to 7% of the study outcomes could be due to the Omicron variant, which might have an insignificant impact on the VE estimates.