Supplementary Material for: Effect of SARS-CoV-2 incidence and immunisation rates on sporadic Creutzfeldt-Jakob disease incidence

Background
Recent case studies and media outlets have hypothesised an effect of SARS-CoV-2 infection and immunisation on the development or progression of neurodegenerative diseases such as Alzheimer’s disease or sporadic Creutzfeldt-Jakob disease (sCJD).
Objectives
This study aims to identify potential associations of SARS-COV-2 infections and SARS-COV-2 immunisation with sCJD incidence, disease duration, and age of onset.
Method
We used data from a prospective sCJD surveillance study in Germany (2016 to 2022) and publicly available datasets of SARS-CoV-2 cases and vaccination numbers in Germany for the years 2020-2022. Associations of SARS-CoV-2 incidence and immunisation rates with sCJD incidence were assessed by comparing quarterly and annual cumulative sCJD incidences in the periods before (2016-2019) and during the pandemic (2020-2022).
Results
We could not identify any time-related effect of SARS-CoV-2 incidence or immunisation rate on the sCJD incidence. Moreover, we did not find any sCJD incidence alterations before and during the SARS-CoV-2 pandemic on a federal or state level. The overall sCJD incidence was within expected ranges in the years 2020 to 2022. There were no changes in age of onset and clinical disease duration in these years.
Conclusions
We found no evidence supporting a short-term effect of the pandemic on sCJD incidence. However, considering the extended pre-clinical phase of sCJD, continued surveillance is needed to identify potential future incidence alterations.