Categorization of yellow fever risk in paraguay after the introduction of the yellow fever vaccine to the regular vaccination schedule

Introduction: Yellow Feveris a disease with a wide spectrum of symptoms. Objective: To identify the Sanitary Regions of Paraguay with high, medium and low risk of yellow fever. Materials and Methods: Observational descriptive, cross-sectional study conducted from 2006-2021. Demographic variables: age, Sanitary Region, population, vaccination coverage against yellow fever and epidemiological density (presence of the reservoir and A. aegypti (vector), proximity and migration to epizootic areas. A risk matrix was developed and applied to each region: score >8 considered high, 5-7: medium, <4low risk. Results: In the last 5 years, the vaccination coverage was 52-80% (p=0.000047). Coverage: pre-pandemic 76%, post-pandemic 59% (p=0.015).1-16 y. vaccinated: 79.9%, 17 to 59 y: 85.1% (p=0.45). In 2021, almost all health regions had a reservoir of the virus, the vector spread in all Regions, vaccination coverage was <80% in 8 regions, 84-94% in 10, 95 to 100% in 1. Risk of yellow fever by 2021: high: 17 (89%) regions, medium: 2 (11%), low: none, (high vs low p=0.00000001). Conclusion: Large gaps in vaccination, expansion of the vector and presence of the reservoir in almost all regions were found. Regions with high, medium and lowrisk of yellow fever in humans were identified.