Investigators enrolled 452 parents or guardians of children in the first year of life using cluster sampling. The data were collected by household interviews in 2025. The cohort included predominantly younger infants: 78.5% were aged zero to six months. Slightly more than half of the children were male (52.2%). Most respondents were female (88.5%) and identified as non-White (82.7%). The report did not provide additional demographic breakdowns beyond these items in the abstract.
The study design was cross-sectional and analytical. That means the team captured attitudes and knowledge at a single time point rather than following families over time. The source did not report any longitudinal follow-up or linkage to vaccination records within the abstract.
The authors used an adapted, previously validated form administered in-person. Knowledge about childhood vaccination was assessed with six questions and classified into three categories: low, moderate, or high. The abstract did not list the six items or scoring thresholds; those details were not reported in the abstract text.
The study operationalized vaccine hesitancy expansively. Any parent or guardian with at least one response compatible with any of five recognized dimensions — confidence, complacency, convenience, communication, or context — was counted as hesitant. This dichotomous outcome (yes/no) served as the dependent variable in logistic regression models.
Data indicated that overall vaccine hesitancy was present in 31.4% of the sampled parents or guardians. Hesitancy specific to the COVID-19 vaccine accounted for most of that burden: 25.2% of respondents expressed hesitancy toward COVID-19 immunization. By contrast, hesitancy toward other vaccines on the childhood schedule was reported in 6.2% of respondents. The authors did not provide, in the abstract, item-level frequencies for each hesitancy dimension (for example, how many responses were related to confidence versus convenience).
These figures place COVID-19–specific concerns well above hesitancy for routine vaccines within the same population. The abstract did not indicate whether respondents had prior experience with COVID-19 vaccination for older children or adults in the household, which could influence these perceptions.
The study used logistic regression to estimate crude and adjusted odds ratios with 95% confidence intervals and a 5% significance threshold. Adjusted models identified several associations.
Parents or guardians of children aged seven to 12 months had higher odds of reporting vaccine hesitancy compared with those of younger infants (adjusted odds ratio [aOR] 2.16; p = 0.002). This suggests hesitancy rose later in the first year rather than being confined to the immediate postnatal months.
Higher educational attainment was associated with reduced odds of hesitancy (aOR 0.79; p = 0.038). The authors reported that respondents with high knowledge had lower odds of hesitancy (aOR 0.39; p = 0.015). The abstract links this finding to the idea that understanding vaccine-preventable diseases, safety profiles, and expected reactions supports adherence to recommended schedules.
The report did not include, in the abstract, the complete set of covariates entered into the adjusted model or the full numeric outputs (confidence intervals were mentioned as part of the methods but not shown in the abstract). The source text did not supply details on potential collinearity diagnostics, model fit statistics, or sensitivity analyses within the abstract itself.
The study offers a sizable, community-based sample collected through household interviews and uses a previously validated instrument to measure knowledge. Those features strengthen the internal validity of the cross-sectional snapshot.
Limitations are inherent to the design. The abstract notes cross-sectional analytical methods; therefore causality cannot be inferred. The authors did not report verification of self-reported hesitancy against actual vaccination behavior in the abstract. The six-item knowledge scale is described but its item-level content and scoring cutpoints were not provided in the abstract; this restricts interpretation of what ‘high knowledge’ specifically entailed.
Several clinical and programmatic questions remain unanswered in the abstract: which particular knowledge gaps drive hesitancy, whether targeted education would reduce COVID-19–specific hesitancy more than hesitancy toward routine vaccines, and how these attitudes translate into actual uptake over time. The study team did not report follow-up vaccination verification or longitudinal assessment in the abstract; such data would be needed to connect expressed hesitancy with missed or delayed immunizations.
Overall, investigators reported substantial parental hesitancy within the first year of life in this Brazilian cohort, dominated by concerns about the COVID-19 vaccine, and found that higher education and greater knowledge were independently associated with lower odds of hesitancy.