Mass Measles Immunization Campaigns: Reporting and Investigating Adverse Events Following Immunization

Abstract

This set of guidelines is intended to prescribe appropriate procedures for surveillance of and response to adverse events following immunisation (AEFI) during mass measles campaigns. The report begins with a short summary of measles-related AEFI, and introduces a 5-category classification scheme for events: vaccine reactions, programme errors (the most common source of AEFI during campaigns), coincidental reactions, injection reactions, and unknown events. The article discusses each of these causes of reaction and strategies for the prevention and treatment of cases, focusing on programmatic errors and ways to prevent and address them. The document notes several particular patterns of AEFI that point to the source of the reaction - programmatic errors, for example, tend to show up in clusters. Strategies for implementing surveillance systems in areas where no national or regional capabilities exist are also considered.

The body of the document is taken up with a set of guidelines for responding to AEFI. Responses begin with an investigation of the reported events that fall into a set of criteria that reflect the severity of the reaction, the plausible causes, and potential community reaction. Investigation is followed by direct communications with the affected community and with the media. Among the topics covered are the timing of information release, the nature and structure of press statements, and the holding of media conferences. The document closes with some guidelines for evaluating the surveillance of AEFI during campaigns, including assessment of its sensitivity, timeliness, and completeness of reporting and investigation. It also covers the auditing of corrective actions.

Key Communication Points

Following a discussion of AEFI types and surveillance practices, the document includes a section on responding to AEFI, beginning with the decision to investigate reported events. Reported AEFI must be investigated if it:

• may have been caused by programme error
• is a serious event requiring hospitalisation or resulting in death
• is a serious event of unexplained cause, or
• is causing significant parental or community concern.

When deemed necessary, investigations must be commenced promptly and with a sense of urgency in order to prevent further AEFI and to reassure the public. In cases of programmatic error it is important for investigative bodies to refrain from blaming individuals and to focus on system problems. Investigations should start immediately and should be fully resourced and accompanied by increased surveillance activities. Working hypotheses, once developed, should not be communicated until they have been confirmed to a reasonable degree of certainty. Premature statements and overconfident estimates of risk estimates should be avoided, as they can lead to distrust if they turn out to be incorrect. It is better to, "[a]dmit uncertainty, investigate fully, and keep the community informed." Nevertheless, the guidelines stress that while corrective actions should be implemented as soon as possible, "It is never appropriate to discontinue the immunization programme while awaiting the completion of the investigation."

Community and media communication strategies are vital and should include emphasis on the known benefits of immunisation in preventing serious disease compared with uncertainty relating to AEFI; supporting data should be presented and made available for review. Discussion of causality should focus on the likelihood of programme error or coincidental illness until evidence suggests otherwise and should be accompanied by assurances that the appropriate action is being taken to ensure safety.

Media relations personnel should have been selected prior to the AEFI and should have an understanding of the media perspective. That is, they should be apprised of the fact that some journalists are interested in stories that sell, are prone to dramatisation, and tend to focus on the number of events and fail to present them in the context of the rate of occurrence relative to the numbers of immunisations. The response of the health community to the AEFI should be seen as "compassionate, with careful and expert investigation" - communications should never convey an overly clinical or impersonal stance and should focus on concern for safety.

Media conferences are best held early as possible, when media interest is greatest. Furthermore, they should not be limited to exclusive groups of reporters; this will help prevent the circulation of rumours and reduce the sensationalising of events. Conferences must, however, be used judiciously, as they can cause problems if spokespersons are inadequately prepared or if the media is already hostile. Where possible, they should include third-party stakeholder groups that can voice their support for the immunisation programmes. Preparations for conferences should include:

• The key messages to be communicated.
• Identification of appropriate spokespersons and supporting voices.
• A media kit for both media and community leaders containing concise press releases, background information, and 'questions and answers' to likely public concerns.

Press statements should include the following:

• Complete account of events in non-expert language that conveys the context in which the AEFI occurred.
• Information as to whether the event is ongoing or isolated.
• A statement on the cause of the event, if identified with reasonable certainty.
• Corrective actions that have or will be taken including further plans for investigation.

The guidelines contain an annex (F) that provides specific principles and actions for spokespersons when communicating with the media. This includes a further list of points to emphasise, a discussion of presentation style (so as to convey honesty, caring, and seriousness), and techniques for dealing with hostile interviewers and bridging to other subjects.