Indicators of the National Immunization Program for children under one year old: time trend in Maranhão, Brazil, 2010 to 2021

Abstract We aimed to analyze the trend of indicators National Immunization Program (acronym in Portuguese. PNI) children under one-year-old and classify municipalities regarding risk transmission vaccine-preventable diseases (RTVPD) Maranhão from 2010 2021. This ecological time series study was based on secondary data vaccination coverage (VC). homogeneity (VCH). proportion abandonment (PA). RTVPD. with state for vaccines national children’s calendar. Prais-Winsten regression estimated trends (α=5%) indicators’ annual percentage change (APC). identified fluctuating discrepant VC between vaccines. a decreasing (p < 0.01). except those against Hepatitis B = 0.709) oral human rotavirus 0.143). The sharpest falls were Yellow Fever (APC 12.24%) BCG 12.25%) All VCH rates lower than expected. drop 2014 APC 5.75% (Pneumococcal 10; p 0.033) 14.02% (Poliomyelitis; observed an increasing PA Pentavalent 4.91%; 0.01) Poliomyelitis 3.55%; increase 52.54% 2015 extremely high 0.025) 0.028) PNI deteriorated. reaffirming susceptibility emergence diseases.