Analysis of 2023 surveillance data across US states reveals COVID-19 vaccination coverage as the strongest protective factor against Long COVID prevalence, while higher SARS-CoV-2 incidence rates modestly increased Long COVID risk. Surprisingly, hospitalization rates and chronic disease burden showed no independent association with Long COVID prevalence when accounting for vaccination and infection rates. This state-level ecological analysis represents one of the largest geographic assessments of Long COVID patterns, encompassing population-level data from the Behavioral Risk Factor Surveillance System. The findings reinforce vaccination's protective benefits beyond preventing severe acute illness, extending to long-term post-viral complications that affect millions of Americans. However, the ecological design cannot establish individual causation, and self-reported Long COVID diagnosis introduces potential measurement bias. Geographic variations in healthcare access, testing availability, and population demographics may also influence these patterns. As this preprint awaits peer review, the results could shift with additional analysis. The research adds compelling population-level evidence supporting continued vaccination efforts as a primary Long COVID prevention strategy, though individual risk factors and optimal vaccination timing require further investigation through longitudinal cohort studies.