Several studies have shown that people with kidney failure who undergo dialysis develop weaker antibody responses after COVID-19 vaccination than people in the general population, but new research indicates that the immune responses of these people are still able to protect against SARS-CoV-2 infection and severe COVID-19. The findings are published in JASN.
For the study, Matthew Oliver, MD, MHS (Sunnybrook Health Science Centre, University of Toronto, Ontario Health) and colleagues analyzed the health records of 13,759 people receiving maintenance dialysis between Dec. June 30, 2021; 17% of who were unvaccinated, 83% of whom had received at least 1 dose of COVID-19 mRNA vaccine.
The study was conducted among the entire maintenance dialysis population of Ontario, the most populous province in Canada. The population was multicultural and included patients receiving both home dialysis and center hemodialysis.
Patients on maintenance dialysis often have weakened immune systems and many are unable to self-isolate as they must attend dialysis treatments 3 times a week at a dialysis center. The reduction in hospitalizations and deaths is very significant in this population because approximately two-thirds of these patients were hospitalized and 1 in 4 died when infected with SARS-CoV-2 early in the pandemic.”
Dr. Matthew Oliver, MD, MHS, Sunnybrook Health Science Centre, University of Toronto, Ontario Health
Dr. Oliver and his team found that there were 663 SARS-CoV-2 infections along with 323 hospitalizations and 94 deaths during the study period. Compared to unvaccinated people, those who had received 1 dose of COVID-19 vaccine were 41% less likely to become infected with SARS-CoV-2 and 46% less likely to develop a severe form of COVID-19 requiring treatment. hospitalization or resulting in death, and those who had received 2 doses were 69% and 83% less likely to become infected or suffer serious illness, respectively. The risk of hospitalization in the unvaccinated group was 52% and the mortality rate was 16%, while the risk of hospitalization in the 2-dose group was 30% and the mortality rate was 10% .
There was no significant difference in vaccine effectiveness between age groups, dialysis mode, or vaccine type (Pfizer-BioNTech or Moderna).
“Governments and healthcare providers prioritized patients on maintenance dialysis for early vaccination against COVID-19 in many countries, including the United States and Canada. This strategy was correct and significant because our results show that 2 doses of an mRNA vaccine significantly protected this population, preventing many hospitalizations and deaths and reducing the burden on patients, families and the healthcare system,” said the Dr. Oliver “The efficacy of the vaccines was lower than that seen in studies in the general population, but still provided substantial protection.” It is now recommended that all adults and adolescents, especially those who are immunocompromised, receive a third dose of COVID-19 vaccine to ensure an optimal immune response.
American Society of Nephrology
Oliver, MJ, et al. (2022) Vaccine efficacy against SARS-CoV-2 infection and severe outcomes in the maintenance dialysis population in Ontario, Canada. Journal of the American Society of Nephrology. doi.org/10.1681/ASN.2021091262.