COVID-19 misinformation was widespread during the pandemic and its exposure was associated with demographic characteristics, resulting in health disparities. Although misinformation reduces acceptability of prevention measures (e.g., vaccine uptake), its impact on COVID-19 mortality has not been quantified nor potential effectiveness of mitigation strategies been evaluated. Understanding the impact of misinformation and developing interventions to combat it is necessary to create an informed path to recovery and to better prepare for future challenges as misinformation will only accelerate given the advances in generative AI. We propose to: 1) estimate the number of excess SARS-CoV-2 infections and COVID-19-related deaths attributable to vaccine misinformation in San Diego County stratified by race/ethnicity; 2) conduct workshops to co-create potential anti-misinformation interventions with CDPH and San Diego County based on analyses from Aim 1 on the impact of misinformation; and 3) investigate the potential of anti- misinformation interventions to mitigate these excess infections and deaths.