key: cord-0856818-3enep993
authors: Frantzen, Luc; Cavaille, Guilhem; Thibeaut, Sandrine; El-Haik, Yohan
title: Efficacy of the BNT162b2 mRNA Covid-19 Vaccine in a hemodialysis cohort
date: 2021-04-24
journal: Nephrol Dial Transplant
DOI: 10.1093/ndt/gfab165
sha: 99416bc607b69f7375838d6c2f323bdb10113ab2
doc_id: 856818
cord_uid: 3enep993

nan

Nephrologists call for priority access to COVID-19 vaccination in patients receiving in-center hemodialysis 1 for two main reasons: a very high risk of SARS-CoV-2 infection compared with the general population (5-16 times more likely 2 because they travel to their dialysis center 3 times a week and are surrounded by other patients and caregivers) and also a particular high mortality rate (close to 20%) when infected by SARS-CoV-2 3 . Our team is taking care of 470 in-center hemodialysis patients in Marseille and its surroundings, a region severely affected by COVID-19. As soon as vaccination has been prioritized for our patients, we proceeded to a large-scale campaign as of January 18 th 2021, when the first injections were administered. Nevertheless, a major downside is the vaccine hyporesponsiveness among such immunecompromised patients often showing disappointing seroconversion rates (for example a 44% rate following a double-dose vaccination schedule for hepatitis B 4 ). In this context and given the lack of data on COVID-19 vaccination in dialysis, we decided to evaluate the vaccine response of our patients by serology testing in order to optimize their future management.

We proposed the COVID-19 vaccination -two injections three weeks apart of the BNT162b2 mRNA COVID-19 vaccine -to all our in-center hemodialysis patients. The exclusion criteria were a lack of consent or a SARS-CoV-2 infection less than three months old. The patients were vaccinated in their dialysis center (the vast majority during their dialysis session). Vaccination efficacy was assessed 1 month after the second injection by quantifying antibodies directed against the Spike protein using the Elecsys® Anti SARS-CoV-2 S enzyme immunoassay (which presents a high correlation with neutralizing antibodies).

As of early March, 70% of our cohort (326 patients) had received the two injections (three weeks apart) of the BNT162b2 mRNA COVID-19 vaccine. Vaccine tolerability was excellent with no serious adverse event on the overall cohort. The first results, regarding 244 patients, show a very high response rate: 91% present a positive antibody titer (with a cut-off fixed at 15 U/mL for the Elecsys® Anti SARS-CoV-2 S test). The baseline characteristics of the patients and their immune response are shown in Table 1 and 2. Older patients were less likely to present an antibody response. There was also no response to vaccination among all the patients undergoing chemotherapy (3/3) or under immunosuppression (1/1).

The results go far beyond what is usually seen with other vaccines in this hyporesponsive population with a 91% antibody positivity rate, with 60% of the patients presenting an antibody level above 200 U/ml correlating with maximal neutralizing capacity in the neutralization assays for the Elecsys® Anti SARS-CoV-2 S test. However, some of our patients show a rather weak response and a recent study 5 reported lower antibody levels in dialysis patients compared to the general population. The consequences may be a lower vaccine efficacy and a shorter period of immunoprotection. It is therefore necessary to consider reinforced vaccination schedules. Nevertheless, in parallel to these biological results, we have witnessed a spectacular decrease in new case occurrences as of mid-February (three weeks after the first injections) in our dialysis centers. This clinical and biological response to a mRNA Covid-19 vaccination among a highly vulnerable population is extremely promising. Studies to assess vaccine efficacy in this population in the real-word setting are needed.

The urgent need to vaccinate dialysis patients against severe acute respiratory syndrome coronavirus 2: a call to action

Incidence, characteristics, and outcome of COVID-19 in adults on kidney replacement therapy: a regionwide registry study

Sociodemographic features and mortality of individuals on haemodialysis treatment who test positive for SARS-CoV-2: a UK Renal Registry data analysis

Practical Guide to Vaccination in All Stages of CKD, Including Patients Treated by Dialysis or Kidney Transplantation

Humoral Response to the Pfizer BNT162b2 Vaccine in Patients Undergoing Maintenance Hemodialysis

The authors declare that the results presented in this paper have not been published previously in whole or part. None of the authors does present a conflict of interest.