advanced search

<< Back To Home

- - - VACCINE HESITANCY

Saturday, 25th of May 2013

• VACCINE HESITANCY

Vaccine hesitancy and refusal is not a new phenomenon, although more attention has been paid to it in recent years. The concept of vaccine hesitancy is reflected in the GVAP as the value of vaccines to individuals and communities. Vaccine hesitancy occurs when an individual delays or refuses to accept a vaccine that is otherwise available; it exists on a spectrum, with some people accepting selected vaccines, and some refusing all vaccines. There are, of course, several other causes of non-vaccination such as access, supply limitations and cost.

SAGE was presented with a definition and framework for vaccine hesitancy that relates to issues of confidence (e.g. trust), complacency (e.g. perceived risk of disease), and convenience (e.g. health systems). There are many contextual influences, individual/social group influences, and vaccine-specific and vaccination-specific issues. Examples include influence of the media, experience with past vaccination, and knowledge of vaccine-preventable diseases. There is a need to identify the key determinants in each specific situation to determine the best strategy to address it. A literature review was carried out to assess the causes and impact of vaccine hesitancy, identifying studies from all WHO regions.

The number of articles published in the last 5 years has doubled, many of which focus on human papillomavirus and influenza vaccines. Factors that were identified in the review as related to vaccine hesitancy could serve either as promoters or barriers, depending on the context.

In a preliminary review of strategies implemented to address vaccine hesitancy, it was found that few strategies in the published literature have been evaluated for effectiveness. Most evaluations of strategies are limited to outcomes such as knowledge and awareness, but the relationship between knowledge, awareness and impact is unclear. The published literature is limited, especially from regions where the majority of the worlds children live. A review of the grey literature will be performed drawing in particular on the experience with strategies used to address polio vaccine refusal. More broadly, lessons can also be drawn about refusal of other health interventions and strategies to address it.

The impact of vaccine hesitancy on immunization programmes is not fully understood, in part because of the lack of metrics, and the lack of investigation in most countries. SAGE recognized the importance of measuring vaccine hesitancy with feasible readily applicable indicators, noting that the SAGE proposed GVAP indicators for vaccine hesitancy are currently being field tested and will be reviewed.

SAGE recognized that research is needed in this area, including the need to develop evidence-based strategies and to assess and quantify the impact of hesitancy on immunization programmes overall. In many settings training of researchers in behavioural research and capacity building will be needed to sensitize countries to the issues around vaccine hesitancy.

SAGE recognized that the working group had completed a significant amount of background work which provided a valuable contribution to understanding vaccine hesitancy, and stressed that vaccine hesitancy remains a major concern in all regions and all countries in different populations and at different times. SAGE recommended that the working group reconsider the name and definition of vaccine hesitancy to avoid confusion and ensure that hesitancy is discussed with a common understanding. SAGE suggested that the definition include “when uptake of a vaccine or immunization programme in a community is lower than would be expected in the context of information given and services available”.

SAGE endorsed the effort to review successful interventions in health-related fields beyond immunization, aiming at improving confidence and increasing demand SAGE supported the development of diagnostic tools to identify the context-specific cause(s) of hesitancy and to differentiate hesitancy from the many other reasons why children are not vaccinated or under-vaccinated.

Such tools would help guide strategies to address the underlying causes. SAGE recommended that interviews with immunization managers could be useful to understand challenges on the ground in a variety of contexts. There was agreement there should be recommendations for evidence-based strategies, for which different methodologies could be used, such as probe studies. While these strategies have so far focused on responding to vaccine  hesitancy, attention should also be paid to where vaccine hesitancy could potentially become a problem following introduction of new vaccines or new services.

Recommendations should be developed with regard to demand creation and proactive interventions. SAGE recommended close linkages and interaction with key WHO and UNICEF initiatives to address the unvaccinated or under-vaccinated groups and relevant interventions.