Banca de DEFESA: JULIANA ISCARLATY FREIRE DE ARAUJO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : JULIANA ISCARLATY FREIRE DE ARAUJO
DATE: 09/09/2026
TIME: 08:00
LOCAL: REMOTO-VIDEOCONFERÊNCIA
TITLE:

EVALUATION OF THE VACCINATION RATE IN BRAZIL FROM 2013 TO 2024: CORRELATION BETWEEN VACCINE HESITANCY AND SOCIAL MEDIA USE

KEY WORDS:

Vaccination. Vaccination rate. Time series. Vaccine hesitancy. Social media. YouTube. Misinformation. Discourse Analysis.

PAGES: 183
BIG AREA: Ciências da Saúde
AREA: Saúde Coletiva
SUMMARY:

Immunization has become established as one of the most cost-effective public health interventions for reducing morbidity and mortality from infectious diseases, with the National Immunization Program (Programa Nacional de Imunizações — PNI) serving as an international reference due to the free provision and comprehensive scope of its vaccination schedule. However, the maintenance of these achievements is threatened by vaccine hesitancy, a multifactorial phenomenon intensified by the infodemic and the circulation of vaccination narratives on social media. In this context, the present study aimed to assess vaccination rates in Brazil over the historical series from 2013 to 2024 and their relationship with vaccination-related trends disseminated on social media, specifically on YouTube. This study articulates three complementary methodological approaches: 1) a systematic literature review, registered in PROSPERO (CRD42024581283); 2) an observational epidemiological time-series study, using data from SI-PNI/DATASUS analyzed through Joinpoint and Prais–Winsten models and spatial analysis (Moran’s Index and bivariate LISA); 3) a mixed-methods study, with a convergent parallel design, of videos published on YouTube between 2013 and 2024, combining quantitative characterization of a reference corpus of 25,579 videos, Natural Language Processing, and Discourse Analysis of a sample of 96 videos classified into four discursive positions (neutral, pro-vaccine, tendency toward misinformation, and tendency toward anti-vaccination). The results showed that the infodemic operates as a contemporary social determinant of health, with the potential both to undermine and to strengthen vaccine uptake; that adult vaccination in Brazil presents a predominant pattern of statistical stability associated with persistently insufficient vaccination coverage, indicating structural fragility; that the circulation of vaccination-related discourses on YouTube is marked by disputes over authority, trust, and legitimacy, with porous boundaries between the identified discursive positions; and that the exploratory association between the volume of published videos and vaccination rates by immunobiological agent does not allow causal inferences, proving to be heterogeneous and mediated by political and institutional determinants. It is concluded that the relationship between social media and vaccination rates in Brazil is multifactorial. No consistent statistical association was identified between the volume of videos published on YouTube and vaccination rates during the analyzed period. However, the qualitative and retrospective analysis demonstrated that the platform constitutes a space of mediatization and dispute over meanings surrounding vaccination, in which different regimes of authority, trust, and legitimacy are articulated. These findings reinforce the need for coordinated and intersectoral health communication strategies that consider not only the amount of information available, but also the meanings and contexts in which such information is produced and circulated, in order to address vaccine hesitancy.

 

COMMITTEE MEMBERS:
Presidente - 1879353 - FABIA BARBOSA DE ANDRADE
Interna - 2262871 - ANA ELZA OLIVEIRA DE MENDONCA
Interna - 2568454 - ELISANGELA FRANCO DE OLIVEIRA CAVALCANTE
Externo à Instituição - LEONARDO FERNANDES NASCIMENTO
Externo à Instituição - RODRIGO PINHEIRO DE TOLEDO VIANNA - UFPB