Understanding the Behavioural and Social Drivers of Childhood Vaccination Uptake: A Qualitative Study in Cape Town, South Africa

Background: Childhood vaccination remains the cornerstone of public health strategy, substantially reducing global morbidity and mortality, yet suboptimal uptake persists in many settings. In South Africa, the challenge is evident, as evidenced by persistent outbreaks of vaccine-preventable diseases. Addressing localised immunisation shortfalls requires elucidating the complex interplay of factors beyond conventional access barriers. This sub-study fills an important empirical gap by thoroughly analysing the demand-side factors from the viewpoint of primary service recipients. Methods: Utilising an exploratory qualitative research design, thematic analysis was applied to interview data (n=25 caregivers) collected via a purposive sampling strategy designed to capture maximum variation in experiences within targeted low-uptake sub-districts. Interpretation of the data was systematically guided by the World Health Organization’s Behavioral and Social Drivers (BeSD) framework. The latter consists of four domains, namely, “Thinking and Feeling”, “Social Processes”, “Motivation”, and “Practical Factors”. Findings: Analysis across the BeSD domains revealed a paradox: a remarkably high level of caregiver motivation was systematically challenged by widespread practical barriers. In the Thinking and Feeling domain, widespread conviction regarding the vital benefits of vaccination co-existed with significant anxiety concerning minor side effects (e.g., pain and fever), which sometimes precipitated missed subsequent appointments. Caregivers frequently accepted immunisation as a social routine despite having limited knowledge of the diseases it prevents. Social Processes demonstrated that while decision-making authority rested primarily with mothers, compliance relied on delegating logistical responsibilities to extended family members. Critically, reports of poor communication, judgment, or negative attitudes among healthcare workers undermined trust and acted as barriers to sustained engagement. Within the Practical Factors domain, structural constraints frequently overshadowed high intent, with pervasive issues such as long waiting times and financial costs cited as the main reasons for missed appointments. Conclusion: Caregiver acceptance remains robust, but attainment of optimal coverage is constrained by systemic failures in patient-provider communication and persistent logistical barriers within the public healthcare delivery system. Strategic public health interventions must therefore move beyond addressing only attitudinal opposition to prioritise targeted efforts that mitigate structural constraints and reinforce personalised, empathetic communication to sustain caregiver confidence and adherence.