This appendix provides additional information about the study on the waning immune humoral response to the BNT162b2 COVID-19 vaccine over 6 months. The study included 697 healthcare workers (HCW) who were tested for SARS-CoV-2 antibodies. The study used PCR testing for SARS-CoV-2 detection and antibody detection tests, including IgG and neutralizing antibody (NeutAb) assays. The study also included a subgroup of HCW with specific comorbidities, such as hypertension, diabetes, and immunosuppression. The study used linear mixed models to analyze the kinetics of IgG and NeutAb levels over time. The IgG levels declined more rapidly in older men, while NeutAb levels declined more slowly after 70 days. The study found that BMI and comorbidities significantly influenced antibody levels. The results showed that higher BMI and more comorbidities were associated with lower antibody levels. The study also included a computer-based questionnaire to collect baseline characteristics of the study population. The questionnaire was reviewed and approved by the Institutional Review Board of the Sheba Medical Center. The study used various abbreviations, including IgG, NeutAb, BMI, and S/CO. The study found that the expected and observed geometric mean titers (GMTs) of IgG and NeutAb varied across different periods. The study also included figures showing the monthly trajectory of antibodies and the correlation between IgG and NeutAb levels. The study was supported by references from multiple sources, including clinical trials and studies on SARS-CoV-2.This appendix provides additional information about the study on the waning immune humoral response to the BNT162b2 COVID-19 vaccine over 6 months. The study included 697 healthcare workers (HCW) who were tested for SARS-CoV-2 antibodies. The study used PCR testing for SARS-CoV-2 detection and antibody detection tests, including IgG and neutralizing antibody (NeutAb) assays. The study also included a subgroup of HCW with specific comorbidities, such as hypertension, diabetes, and immunosuppression. The study used linear mixed models to analyze the kinetics of IgG and NeutAb levels over time. The IgG levels declined more rapidly in older men, while NeutAb levels declined more slowly after 70 days. The study found that BMI and comorbidities significantly influenced antibody levels. The results showed that higher BMI and more comorbidities were associated with lower antibody levels. The study also included a computer-based questionnaire to collect baseline characteristics of the study population. The questionnaire was reviewed and approved by the Institutional Review Board of the Sheba Medical Center. The study used various abbreviations, including IgG, NeutAb, BMI, and S/CO. The study found that the expected and observed geometric mean titers (GMTs) of IgG and NeutAb varied across different periods. The study also included figures showing the monthly trajectory of antibodies and the correlation between IgG and NeutAb levels. The study was supported by references from multiple sources, including clinical trials and studies on SARS-CoV-2.