### SARS-CoV-2 Vaccine Response Calculator for KTR

We present a calculator for predicting the individual chance of achieving serological response after third or fourth vaccination against SARS-CoV-2 for previously seronegative, COVID-naive kidney transplant recipients.

We implemented two risk equations that are based on demographic, clinical and laboratory parameters and have been developed based on vaccination data from 590 patients at Charité Berlin.

The 20-variable risk equation showed the better performance during internal and external validation, whereas the 10-variable risk equation is more easily implementable in routine clinical care. Both risk equations showed good predictive performance in four independent, international validation cohorts. Plase note that the risk calculator should not be used, if the following variables are unknown: medication data, eGFR, hemoglobin level, lymphocyte count, or SARS-CoV-2 antibody status before vaccination. Please find the cutoffs used for the different antibody tests in our Preprint. Note that this work is not peer-reviewed yet.

For research purposes only.