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Member Research & Reports

Member Research & Reports

Michigan Researcher Finds that Reports of Adverse Effects from Vaccines Influence Perception Regardless of Conscious Belief

Controversy surrounding the necessity and safety of vaccines in recent years have made public perception about them an important area of study in the field of public health.

Dr. Brian J. Zikmund-Fisher
[Photo: Dr. Brian J. Zikmund-Fisher]

SPH’s Dr. Brian Zikmund-Fisher, associate professor in the health behavior and health education department, teamed up with researchers from The University of Missouri-Columbia to study how the exposure to data from the Vaccine Adverse Event Reporting System (VAERS) influenced people’s attitudes towards vaccination and the roles of the CDC and FDA in protecting citizens from potential dangers associated with vaccines.

When death or serious harm occurs following administration of a vaccine, it is required that it be reported to VAERS so it may be monitored and followed-up by the CDC. However, the entry of information into VAERS is not reserved only for health professionals, nor is the viewing of what is entered. It is a totally public database. Furthermore, the reporting of an adverse event does not necessarily mean that it was caused by the vaccine.

To observe what power VAERS data had to shape public perception of vaccines, this study was designed in which 1,200 people were surveyed about the HPV vaccine (chosen because it is historically under-used) after having been divided into three groups. One group received the standard statement from the CDC that accompanies the HPV vaccine. The second group was educated about the existence, contents, and purpose of VAERS as well as told the number of deaths and permanent disabilities that had been reported in relation to the HPV vaccine. The third group received the same information as the second group, but in addition were able to read the adverse event reports in detail.

Though it was expected that the third group, having received details about the actual adverse events, would realize that many of the events were not actually caused by the vaccine, the addition of detailed information actually caused the third group to show significant declines in both vaccine acceptance and trust in the CDC.

What was even more puzzling about these results was that among these same subjects who reported lower acceptance of vaccines, the majority of them said that they believed few or even none of the reported adverse events were actually caused by vaccines. This contradiction indicates that reading accounts of adverse events following vaccination may influence one’s attitudes towards the vaccine regardless of whether one actually believes the harm was accurately attributed to the vaccine. In the case of VAERS, it seems the emotional response may overshadow the rational one.

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