VACCINE, MEASLES, AND ENDEMIZATION – SPATIAL-TEMPORAL ANALYSIS OF VACCINATION COVERAGE AND RISK OF MEASLES ENDEMIZATION IN BRAZILIAN CAPITALS (2010 – 2024)

Abstract

In recent decades, Brazil has witnessed a concerning decline in measles-mumps-rubella (MMR) vaccine coverage, especially regarding the second dose, which is crucial for ensuring herd immunity against measles. In this context, the present study aims to conduct a spatial-temporal analysis of measles vaccination coverage in Brazilian capitals between 2010 and 2024, with special attention to the risk of endemic resurgence due to low adherence to the complete vaccination schedule. The central research question is: to what extent do capital-specific data reveal a sharp decrease in second-dose coverage that could favor the endemic reemergence of measles in certain urban areas? Based on secondary data from DATASUS/TabNet and previously published studies, the article identifies significant geographic and temporal asymmetries: while first-dose coverage averages over 75% in most capitals, second-dose rates are critically low, often below 50%, as seen in Natal (19% dropout) and João Pessoa (14.7%). Historically, coverage peaked between 2013 and 2016 (≥ 95%), followed by an abrupt decline between 2019 and 2021, coinciding with the pandemic period. Theoretically, the study draws on works by Alves (2021), Aminzadeh (2017), Anderson et al. (2018), Aven (2017), Beck (1999), Figueiredo (2016), Fleury & Ouverney (2012), Galea (2021), Garvey (2008), Heymann (2004), Hotez (2018), Larson (2020), Last (2000), Offit (2010), Ramos (2020), Santos et al. (2024), Schwarcz & Starling (2020), Souza (2021), Timmreck (1998), UNICEF (2020; 2023), Vieira-da-Silva & Almeida Filho (2009), among others. This is a qualitative (Minayo, 2007), bibliographic and descriptive (Gil, 2008) study, guided by a comprehensive analytical approach (Weber, 1949). The findings reveal high dropout rates for the second MMR dose, especially in cities like Natal and João Pessoa. Although first-dose coverage exceeds 75%, poor adherence to the second dose undermines herd immunity and facilitates measles reendemization. The sharp decline from 2019 to 2021 aligns with the pandemic and rising vaccine hesitancy. Risk “urban clusters” were identified, calling for equitable public policies and effective surveillance and communication strategies.