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, Hladunewich M, Oliver MJ, Levin A. COVID-19 vaccine effectiveness among patients with maintenance dialysis; Observations from population level cohort studies in 2 large Canadian provinces. Can J Kidney Health Dis. 2023 Jun 21;10:20543581231181032. doi: https://doi.org/10.1177/20543581231181032.

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 Canadian Journal of Kidney Health and Disease, found that COVID-19 vaccines were highly effective in preventing infection and severe outcomes among patients on maintenance dialysis in both British Columbia and Ontario. This was true even when accounting for differences between the two provinces in the number of pandemic waves, COVID-19 infection rates in the community, and vaccination strategies. This study was led by Dr. Michael Oliver in collaboration with Dr. Michelle Hladunewich (both from University of Toronto).

Key findings:

  • The risk of developing COVID-19 infection was 64% less for patients in BC and 41% less for patients in Ontario after receiving one vaccine dose. After two doses, the risks were 80% less in BC and 69% less in Ontario, respectively. However, there was no statistically significant difference between the two provinces in vaccine effectiveness after one or two doses.
  • The risk of developing COVID-19-related hospitalization or death was reduced by 54% for patients in BC and 46% for patients in Ontario after receiving one vaccine dose, and by 75% and 83%, respectively, after two vaccine doses (although the differences in risk reduction between the two provinces were not statistically significant).
  • Despite differences in the number of pandemic waves, COVID-19 infection rates in the community, and vaccination strategies in BC and Ontario, there were no statistically significant differences in vaccine effectiveness against COVID-19 infection and severe outcomes between the two provinces.

These findings highlight the importance of COVID-19 vaccination for individuals receiving maintenance dialysis and suggest that the approved vaccines can provide significant protection against the virus, irrespective of regional variations in the pandemic. To further understand vaccine effectiveness across Canada, future studies could pool data from multiple regions for nationally representative estimates of vaccine effectiveness.

This study included 4,284 patients from a population-level registry in British Columbia who were already on maintenance dialysis or initiated dialysis therapy from December 14, 2020 to December 31, 2021. The vaccine effectiveness study using Ontario data included 13,759 patients who were already on maintenance dialysis or who initiated dialysis therapy from December 21, 2020, to June 30, 2021.