Kidney Week

Abstract: TH-PO914

Efficacy of COVID-19 Vaccination in Dialysis Patients: A Prospective Multicenter Study

Session Information

• COVID-19: Vaccines and Outcomes ESRD/KTR
  November 03, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
  Abstract Time: 10:00 AM - 12:00 PM

Category: Coronavirus (COVID-19)

• 000 Coronavirus (COVID-19)

Authors

• Ostermaier, Claudia, Philipps-Universitat Marburg Fachbereich Medizin, Marburg, Hessen, Germany

Claudia Ostermaier,

• Kamalanabhaiah, Sahana R., Philipps-Universitat Marburg Fachbereich Medizin, Marburg, Hessen, Germany

Sahana R. Kamalanabhaiah,

• Haas, Christian Stefan, Philipps-Universitat Marburg Fachbereich Medizin, Marburg, Hessen, Germany

Christian Stefan Haas,

• Keller, Christian, Philipps-Universitat Marburg Fachbereich Medizin, Marburg, Hessen, Germany

Christian Keller,

• Hoyer, Joachim, Philipps-Universitat Marburg Fachbereich Medizin, Marburg, Hessen, Germany

Joachim Hoyer,

Background

Dialysis patients are considered to be at increased risk for SARS-CoV-2 infections. Thus, they were prioritized for early vaccination. However, early data suggested that seroconversion rates may be lower in this population, consistent with the reduced response rate to vaccination against hepatitis B, pneumococcus or influenza. The objective of this study was to evaluate the efficacy of COVID-19 vaccines in this cohort with respect to seroconversion, and to identify potential risk factors for nonresponding.

Methods

We conducted a prospective, multicenter study in chronic hemodialysis patients at 4 dialysis facilities in central Germany, starting April 2021. Blood samples were taken prior to 1^st vaccination, before 2^nd vaccination, 7-14 days after 2^nd vaccination, as well as 60 and 120 days after full vaccination for long-term follow-up. At any study time point, results of COVID-19 antigen tests and clinical symptoms were assessed. Similarily, data was obtained for 1^st or 2^nd booster vaccination. Blood samples for antibody titers were drawn – if applicable – at day 30, 90, 150 and 210 following booster vaccination. To identify potential risk factors, data including underlying condition, comorbidities, lab results, seroresponse to hepatitis B vaccination, immunosuppression and other medication was assessed. Antibody response was defined above a value of 7.1 BAU/l.

Results

After 2 vaccinations, 288 individuals were evaluated; of these, 270 (=93%) developed an adequate antibody response. Although the majority of patients had received a mRNA vaccine, there was no significant difference in the allover response rates compared to vector based vaccines. Age and immunosuppressive medication were found to be significant risk factors for nonresponsiveness to COVID-19 vaccination (p<0.05). Infections dropped following immunization. Of note, 6 months after full vaccination, antibody titers significantly declined. Both, 1^st and 2^nd booster doses resulted in an increase of antibody titers: during the omicron wave, no COVID-19 associated hospital admissions were observed.

Conclusion

COVID-19 vaccination is effective in hemodialysis patients. Like in the general population, only age and immunosuppression are risk factors for not responding to vaccination, thereby having a potential impact on outcome, especially for the wave to come.