Appendices to the Report of the SAGE Working Group on Vaccine Hesitancy

"Media and social media can create a negative or positive vaccine sentiment and can provide a platform for lobbies and key opinion leaders to influence others....Community leaders and influencers, including religious leaders in some settings, celebrities in others, can all have a significant influence on vaccine acceptance or hesitancy."

These are some of the lessons highlighted within this document, which includes appendices associated with a report (see Related Summaries, below) that emerged from a November 2011 meeting of the Strategic Advisory Group of Experts (SAGE) on Immunization, where SAGE noted with concern the impact of reluctance to accept immunisation on the uptake of vaccines reported from both developed and developing countries.

The document begins with an appendix for Section 3 of the report: "Definition of Vaccine Hesitancy, its Scope and Vaccine Hesitancy Determinants Matrix". Here included in the document is a review of models of determinants of vaccine hesitancy, such as the 2011 Determinants of Vaccine Hesitancy Model from Canada (see Figure A3.1), which, while illustrating the wide array of determinants and factors, SAGE felt it to be useful for academic work but too complex for practical application in the field. The Working Group also explored arranging factors that impinge on vaccine hesitancy in a systems approach matrix that grouped factors into 3 main categories (see Table A3.1 and Figure A3.2):

• Contexual influences arising due to historic, socio-cultural, environmental, health system/institutional, economic, or political factors - e.g., "Historic influences such as the negative experience of the Trovan trial in Nigeria can undermine public trust and influence vaccine acceptance, as it did for polio, especially when combined with pressures of influential leaders and media."
• Individual and group influences arising from personal perception of the vaccine or influences of the social/peer environment - e.g., "Trust or distrust in government or authorities in general, can affect trust in vaccines and vaccination programmes delivered or mandated by the government. Past experiences that influence hesitancy can includes system procedures that were too long or complex, or personal interactions were difficult."
• Vaccine/vaccination-specific issues - e.g., "Individuals may hesitate to accept a new vaccine when they feel it has not been used/tested for long enough or feel that the new vaccine is not needed, or do not see the direct impact of the vaccine (e.g. HPV vaccine preventing cervical cancer). Individuals may be more willing (i.e. not complacent) to accept a new vaccine if perception of the VPD [vaccine-preventable disease] risk is high."

Other models explored and evaluated in this appendix include: (i) the complex conceptual model from the World Health Organization (WHO) Regional Office for Europe (EURO) (see Figure A3.3), with factors arranged into opportunity, ability, and motivational categories - with further breakdown into subcategories for each; (ii) WHO EURO's Confidence, Complacency, and Convenience Model (picture above and elaborated in Figure A3.4). "In conclusion the Working Group judged that the 3'C' model was the easiest to grasp and a simplified version of the Working Group Matrix was developed. (See main text) [in Related Summaries, below]."

Appendices for Section 4 regarding "Determinants and Impact of Vaccine Hesitancy in Different Settings" include:

• A systematic literature review on vaccine hesitancy, published on the WHO SAGE website; and
• "Mapping vaccine hesitancy - Country-specific characteristics of a global phenomenon", which is a paper describing a SAGE-recommended interview study that was conducted with immunisation managers (IM) to better understand the variety of vaccine hesitancy challenges existing on the ground. Interviews with 13 selected IMs were conducted between September and December 2013. "Although vaccine hesitancy existed in all 13 countries surveyed, some IMs considered the impact of vaccine hesitancy on immunization programs as a minor problem. The causes of vaccine hesitancy were variable and context-specific suggesting the need to strengthen the capacity of countries to identify context-specific factors and to develop adapted strategies to address them."

Appendices for Section 5: "Vaccine Hesitancy Monitoring and Diagnosis" include: Pilot Test of Vaccine Confidence Indicators 2012, Pilot Test of Revised 2013 Vaccine Hesitancy Indicators, Vaccine Hesitancy Survey Questions Related to SAGE Vaccine Hesitancy Matrix, WHO EUR Tailoring Immunization Program (TIP), and Principles for TIP.

Appendices for Section 6: "Strategies to address Vaccine Hesitancy: Research Gaps and Landscape Analysis" feature: an executive summary of the systematic review on strategies to address vaccine hesitancy; strategies to address vaccine hesitancy: summary of published literature reviews; and a vaccine hesitancy landscape analysis.