Definition
Vaccine hesitancy refers to the delay in acceptance or refusal of vaccines despite the availability of vaccination services. It is a complex, context-specific phenomenon that varies across time, place, and specific vaccines. It is best understood as a continuum ranging from total acceptance to total refusal.
The 3Cs Model (WHO SAGE Working Group)
The determinants of vaccine hesitancy are categorized into three core domains:
- Confidence: Trust in the effectiveness and safety of the vaccine, the reliability of the health system and providers, and the motivations of policy-makers.
- Complacency: Occurs when the perceived risk of vaccine-preventable diseases (VPDs) is low and vaccination is not deemed a necessary preventive action.
- Convenience: Physical availability, affordability, willingness to pay, geographical accessibility, and the quality of immunization services (e.g., language and health literacy).
The 5Cs Model (Psychological Antecedents)
Expands the 3Cs to include:
- Calculation: The individual’s engagement in extensive information searching to weigh risks and benefits.
- Collective Responsibility: The willingness to protect others via one’s own vaccination (herd immunity).
Factors Influencing Hesitancy in India
- Contextual Influences: Historical influences, religion, culture, and socio-economic status.
- Individual/Group Influences: Personal experience with the health system, social norms, and “misinformation” spread via digital media.
- Vaccine-Specific Issues: Mode of administration (injectable vs. oral), new vaccine introductions, and concerns regarding Adverse Events Following Immunization (AEFI).
Management Strategies for the Pediatrician
Effective communication is the cornerstone of addressing hesitancy in clinical practice.
Presumptive Approach
- Instead of asking “What do you think about vaccines?”, use a presumptive statement: “Your child is due for the MMR and Varicella vaccines today.” This normalizes the procedure.
The CASE Approach
- Corroborate: Acknowledge the parent’s concern to build rapport (“I understand you want the best for your child”).
- About: Describe what you know about the concern based on clinical expertise.
- Science: Provide the evidence-based facts regarding the vaccine’s safety and efficacy.
- Explain/Advise: Give a firm recommendation based on the science.
Motivational Interviewing (MI)
- A collaborative, goal-oriented style of communication with particular attention to the language of change. It involves asking open-ended questions, affirming, and summarizing the parents’ viewpoints to resolve ambivalence.
Clinical and Public Health Impact
- Sub-optimal Coverage: Leads to failure in achieving herd immunity thresholds ( related).
- VPD Resurgence: Directly linked to outbreaks of Measles, Pertussis, and Diphtheria in previously well-covered regions.
- Economic Burden: Increased healthcare costs due to preventable hospitalizations and outbreak management.