The role of media and the Internet on vaccine adverse event reporting: a case study of human papillomavirus vaccination

Abstract

Purpose: This study aimed to determine the temporal association of print media coverage and Internet search activity with adverse events reports associated with the human papillomavirus vaccine Gardasil (HPV4) and the meningitis vaccine Menactra (MNQ) among United States adolescents.

Methods: We used moderated linear regression to test the relationships between print media reports in top circulating newspapers, Internet search activity, and reports to the Vaccine Adverse Event Reporting System (VAERS) for HPV4 and MNQ during the first 2.5 years after Food and Drug Administration approval.

Results: Compared with MNQ, HPV4 had more coverage in the print media and Internet search activity, which corresponded with the frequency of VAERS reports. In February 2007, we observed a spike in print media for HPV4. Although media coverage waned, Internet search activity remained stable and predicted the rise in HPV4-associated VAERS reports.

Conclusions: We demonstrate that media coverage and Internet search activity, in particular, may promote increased adverse event reporting. Public health officials who have long recognized the importance of proactive engagement with news media must now consider strategies for meaningful participation in Internet discussions.

Keywords: Internet; Mass media; Meningococcal vaccines; Newspapers; Papillomavirus vaccines; Vaccine Adverse Event Reporting System (VAERS).

Figure 1

Temporal pattern in print media and Internet activity by vaccine type. These panels represent the “volume” of print media reports and Internet search activity relating to HPV4 (dotted line) and MNQ (solid line) in the first 2.5 years post-FDA approval of each respective vaccine. Volume of print media reports was measured as the total number of unique news reports in top circulating U.S. newspapers per month and volume of Internet search activity was measured as the popularity of the search terms “Gardasil” vs. “Menactra” in Google Search per month, normalized and scaled from 0–100. Moderated regression models indicated a significant spike in print media reports in month-9 post-FDA approval for HPV4 but not MNQ, and a significant increase in Internet search activity for HPV4 in months 9–31 for HPV4 but not MNQ.

Figure 2

Temporal pattern in VAERS reporting by vaccine type. This figure represents the total number of VAERS reports per month for HPV4 (dotted line) vs. MNQ (solid line). A moderated regression model found no significant differences in the number of VAERS reports/month between MNQ and HPV4 in months 1–8 post-FDA approval of each respective vaccine. In months 9–31, however, HPV4 was associated with more VAERS reports than MNQ, suggesting that the spike in print media in month-9, post-FDA approval, acted as a transitional event to increase HPV4-associated VAERS reporting.

Figure 3

Internet search activity as a key mediating step towards increased VAERS reports for HPV4 model. The MNQ vaccine remained an included comparison group throughout. Whole lines reflect main effects and are independent of moderation by vaccine type, except when involving the vaccine variable itself (e.g., vaccine directly predicting internet search activity). Dotted-lines reflect relationships unique to the HPV4 vaccine. Notes: ** P-value <0.01 * P-value <0.05