Social Norms, Vaccine Confidence, and Interpersonal Communication as Predictors of Vaccination Intentions: Findings from Slum Areas in Varanasi, India

"Given the strengths of the relationships observed in this study, intervention strategies should focus on enhancing social norms and vaccine confidence to promote vaccination."

In India, childhood immunisation rates among the urban economically poor remain stagnant. In slum areas, economic vulnerability, time scarcity, and limited critical media literacy make individuals increasingly susceptible to vaccine misinformation - a factor often correlated to decreased vaccine confidence. This paper focuses on how social norms, interpersonal communication, and vaccine confidence independently and jointly affect vaccine intentions among caregivers of infants living in six slum areas in Varanasi, India.

Key concepts examined in the study include:

• Social norms: Previous research on vaccination attitudes in Indian slums reveals several considerations for normative influences: reduced prioritisation of preventive health in the face of economic pressures; the transient nature of life, hindering a sense of broader community; and substandard healthcare services that do not foster trust between providers and the community they serve. In these conditions, family members, neighbours, and extended kin networks may have an outsize influence on health decisions. In the literature, social norms have been conceptualised as either descriptive (referring to people's perceptions about the prevalence of a behaviour, such as vaccination) or injunctive (social pressures people feel to conform, such as to have their children vaccinated).
• Interpersonal communication: Unlike laws, which are codified and fixed, norms are fluid and change with the social context in which they operate. Social interactions help individuals understand what is acceptable, expected, or normal in a given context Thus, social norms are understood and negotiated through social interactions, and interpersonal communication is a key element in this process.
• Vaccine confidence, which is the extent to which people believe in the efficacy, benefits, and utility of vaccines. Though vaccine confidence has been shown to be a driver of vaccine uptake, what is less well known is the extent to which vaccine confidence is propagated through interpersonal communication.

Data for this study come from the baseline assessments conducted before implementing the Happy Baby Program, a WhatsApp and chatbot-based intervention to improve vaccination attitudes and intentions. In-person interviews (N = 2,058) were conducted with caretakers of children up to two years old in six slum areas.

Analyses showed that descriptive norms, injunctive norms, interpersonal communication about vaccines, and vaccine confidence were each associated with intentions to vaccinate in both a bivariate and, except for injunctive norms, a multivariate model. In addition, the researchers found significant interactions among these variables, suggesting that the roles of interpersonal communication and vaccine confidence attenuated the relationship between social norms and vaccination intention. Overall, the model explained 46.2% of the variance in vaccine intention.

Specific findings include:

• In line with the theory of normative social behaviour (TNSB), the relationship between descriptive norm and intention to vaccinate was moderated by injunctive norm. When people perceived that most others in their community were vaccinating their children, their own intention to vaccinate was reinforced by the belief that important others also expected them to do so. This finding holds implications for vaccination promotion interventions, emphasising the need to highlight both kinds of norms.
• Intention was significantly lower when high descriptive norm was coupled with low injunctive norm. Thus, from an intervention strategy perspective, the researchers suggest assessing community levels of descriptive and injunctive norm before implementing an intervention. Targeted messages should focus on augmenting the specific norm that is low in the community.
• When vaccination is not the topic of discussion in the community, people rely on their perceptions of norms to make decisions about their own vaccination (perhaps because they have less exposure to vaccine information). When discussion centres around vaccination, however, the influence of social norms on intentions gets attenuated, perhaps because interpersonal communication itself also becomes one of the considerations when people decide whether to get vaccinated or not.
• The relationship between vaccine confidence and intention was stronger when social norms were weak rather than when they were strong. When people have a high level of confidence in vaccines, their normative beliefs appear to be less consequential in shaping their vaccine intentions as compared to when people have a low level of confidence in vaccines (in which case their normative beliefs become more consequential). This finding highlights the important role that interpersonal communication can play in disseminating both truthful and untruthful information about vaccines.

The picture that emerges from these analyses points to vaccine confidence as a key variable. As the researchers explain, from an intervention perspective, promoting confidence in vaccines appears to be one of the most effective strategies because, when confidence levels are high, few other variables (including interpersonal communication and social norms) appear to matter in shaping people's intentions to vaccinate.

In conclusion: "Slum environments present multiple challenges - both social and logistical - for traditional vaccine promotion campaigns to reach vulnerable audiences....In this environment, leveraging social norms for improving immunization appears to be a particularly important task."