The study by Srivastava et al. investigates the long-term durability of antibody responses to SARS-CoV-2 infection and vaccination using longitudinal data from over 8,000 participants in New York City over a 3-year period. The findings challenge the common perception that mRNA-based vaccine-induced immunity wanes quickly. Key results include: 1. **Initial Waning Phase**: After primary immunization, participants with pre-existing immunity mounted higher and faster antibody responses compared to naive individuals, achieving higher steady-state antibody titers. 2. **Stabilization Phase**: Antibody kinetics were characterized by an initial rapid decay followed by a stabilization phase with very slow decay. 3. **Booster Vaccination**: Booster vaccinations equalized the differences in antibody concentration between participants with and without pre-existing immunity, but peak antibody titers decreased with each successive antigen exposure. 4. **Breakthrough Infections**: Breakthrough infections in naive individuals increased antibodies to similar titers as an additional vaccine dose. 5. **Modeling**: A nonlinear mixed-effects model was developed to describe the antibody dynamics, revealing a biphasic decay pattern and providing a personalized immunity score. 6. **Hybrid Immunity**: Individuals with pre-existing immunity and subsequent vaccination showed higher and more stable antibody responses compared to those with only vaccine-induced immunity. 7. **Reactogenicity**: Pre-existing immunity modulated the reactogenicity of consecutive SARS-CoV-2 vaccinations, with more pronounced side effects in participants with hybrid immunity. The study provides strong evidence that SARS-CoV-2 antibody responses are long-lasting, with an initial waning phase followed by a stabilization phase, challenging the notion that vaccine immunity fades quickly.The study by Srivastava et al. investigates the long-term durability of antibody responses to SARS-CoV-2 infection and vaccination using longitudinal data from over 8,000 participants in New York City over a 3-year period. The findings challenge the common perception that mRNA-based vaccine-induced immunity wanes quickly. Key results include: 1. **Initial Waning Phase**: After primary immunization, participants with pre-existing immunity mounted higher and faster antibody responses compared to naive individuals, achieving higher steady-state antibody titers. 2. **Stabilization Phase**: Antibody kinetics were characterized by an initial rapid decay followed by a stabilization phase with very slow decay. 3. **Booster Vaccination**: Booster vaccinations equalized the differences in antibody concentration between participants with and without pre-existing immunity, but peak antibody titers decreased with each successive antigen exposure. 4. **Breakthrough Infections**: Breakthrough infections in naive individuals increased antibodies to similar titers as an additional vaccine dose. 5. **Modeling**: A nonlinear mixed-effects model was developed to describe the antibody dynamics, revealing a biphasic decay pattern and providing a personalized immunity score. 6. **Hybrid Immunity**: Individuals with pre-existing immunity and subsequent vaccination showed higher and more stable antibody responses compared to those with only vaccine-induced immunity. 7. **Reactogenicity**: Pre-existing immunity modulated the reactogenicity of consecutive SARS-CoV-2 vaccinations, with more pronounced side effects in participants with hybrid immunity. The study provides strong evidence that SARS-CoV-2 antibody responses are long-lasting, with an initial waning phase followed by a stabilization phase, challenging the notion that vaccine immunity fades quickly.