The impact of epidemics of vaccine-preventable disease on vaccine uptake: lessons from the 2011–2012 US pertussis epidemic

Abstract

Conventional wisdom suggests that if there is a vaccine that is effective in preventing a disease, vaccine uptake will increase when the disease risk is high. Recent evidence, however, suggests that this may not always be the case. In a study we conducted in Washington State, we found no population-level increase in pertussis vaccination of infants during a pertussis epidemic. In this paper, we aim to review what is known about the history of vaccine uptake during epidemics of vaccine-preventable disease, the challenges facing public health campaigns responding to these epidemics, and how the effect of a vaccine-preventable disease epidemic on vaccine uptake can be studied.

Keywords:

• epidemics
• epidemiological study characteristics
• health communication
• public health
• vaccination

Acknowledgements

The authors would like to acknowledge E Marcuse, J Taylor and E Peters for their contributions to this manuscript.

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Key issues

• An epidemic is defined as the occurrence of more cases of disease, injury or other health condition than expected in a given area or among a specific group of persons during a particular period.

  • – Use of the term epidemic may require extra caution today because current low background levels of vaccine-preventable disease mean that the absolute number of cases needed to reach an epidemic threshold is relatively small.

  • The primary goal of a public health campaign in response to a vaccine-preventable disease epidemic is to increase the vaccine uptake in order to limit the scope and severity of the immediate epidemic and to try and prevent future epidemics.

  • Important components of a public health campaign in response to a vaccine-preventable disease epidemic include the following:

    • – Accurately conveying the risks of disease and putting the risks of adverse events following immunization into perspective, and

    • – Taking into consideration the public’s perception of risk – a highly subjective concept with analytic and emotional content.

    • Public health messages regarding a disease epidemic can be more effective if they are evidence-based, targeted and timely.

    • Longitudinal study designs on an ecologic level (e.g., before-after, interrupted time series) can be employed to examine the effect of epidemics on vaccine uptake.

Notes