Impact of tozinameran (BNT162b2) mRNA vaccine on kidney transplant and chronic dialysis patients: 3-5 months follow-up.

BACKGROUND: Determining the humoral immunogenicity of tozinameran (BNT162b2) in patients requiring chronic renal replacement therapy, and its impact on COVID-19 morbidity several months after vaccination, may guide risk assessment and changes in vaccination policy. METHODS: In a prospective post-vaccination cohort study with up to 5 months follow-up we studied outpatient dialysis and kidney transplant patients and respective healthcare teams. Outcomes were anti S1/S2 antibody responses to vaccine or infection, and infection rate during follow-up. RESULTS: One hundred seventy-five dialysis patients (40% women, 65 ± 15 years), 252 kidney transplant patients (33% women, 54 ± 14 years) and 71 controls (65% women, 44 ± 14 years) were followed. Three months or longer after vaccination we detected anti S1/S2 IgG antibodies in 79% of dialysis patients, 42% of transplant recipients and 100% of controls, whereas respective rates after infection were 94%, 69% and 100%. Predictors of non-response were older age, diabetes, history of cancer, lower lymphocyte count and lower vitamin-D levels. Factors associated with lower antibody levels in dialysis patients were modality (hemodialysis vs peritoneal) and high serum ferritin levels. In transplant patients, hypertension and higher calcineurin or mTOR inhibitor drug levels were linked with lower antibody response. Vaccination was associated with fewer subsequent infections (HR 0.23, p < 0.05). Moreover, higher antibody levels (particularly above 59 AU/ml) were associated with fewer events, with a HR 0.41 for each unit increased in log10titer (p < 0.05). CONCLUSIONS: Dialysis patients, and more strikingly kidney transplant recipients, mounted reduced antibody response to COVID-19 mRNA vaccination. Lesser humoral response was associated with more infections. Measures to identify and protect non-responsive patients are required.

Practical recommendations for kidney transplantation in the COVID-19 pandemic.

Kidney transplantation at the time of a global viral pandemic has become challenging in many aspects. Firstly, we must reassess deceased donor safety (for the recipient) especially in communities with a relatively high incidence of coronavirus disease 19 (COVID-19). With respect to elective live donors, if one decides to do them at all, similar considerations must be made that may impose undue hardship on the donor. Recipient selection is also problematic since there is clear evidence of a much higher morbidity and mortality from COVID-19 for patients older than 60 and those with comorbidities such as hypertension, diabetes, obesity and lung disease. Unfortunately, many, if not most of dialysis patients fit that mold. We may and indeed must reassess our allocation policies, but this must be done based on data rather than conjecture. Follow-up routines must be re-engineered to minimize patient travel and exposure. Reliance on technology and telemedicine is paramount. Making this technology available to patients is extremely important. Modifying or changing immunosuppression protocols is controversial and not based on clinical studies. Nevertheless, we should reassess the need for induction therapy across the board for ordinary patients and the more liberal use of mammalian target of rapamycin inhibitors in transplant patients with proven infection.