Fake News or Weak Science? Visibility and Characterization of Antivaccine Webpages Returned by Google in Different Languages and Countries

Abstract

The 1998 Lancet paper by Wakefield et al., despite subsequent retraction and evidence indicating no causal link between vaccinations and autism, triggered significant parental concern. The aim of this study was to analyze the online information available on this topic. Using localized versions of Google, we searched "autism vaccine" in English, French, Italian, Portuguese, Mandarin, and Arabic and analyzed 200 websites for each search engine result page (SERP). A common feature was the newsworthiness of the topic, with news outlets representing 25-50% of the SERP, followed by unaffiliated websites (blogs, social media) that represented 27-41% and included most of the vaccine-negative websites. Between 12 and 24% of websites had a negative stance on vaccines, while most websites were pro-vaccine (43-70%). However, their ranking by Google varied. While in Google.com, the first vaccine-negative website was the 43rd in the SERP, there was one vaccine-negative webpage in the top 10 websites in both the British and Australian localized versions and in French and two in Italian, Portuguese, and Mandarin, suggesting that the information quality algorithm used by Google may work better in English. Many webpages mentioned celebrities in the context of the link between vaccines and autism, with Donald Trump most frequently. Few websites (1-5%) promoted complementary and alternative medicine (CAM) but 50-100% of these were also vaccine-negative suggesting that CAM users are more exposed to vaccine-negative information. This analysis highlights the need for monitoring the web for information impacting on vaccine uptake.

Keywords: Internet; autism; google; information quality; news; news media; public understanding of science; vaccines.

Figure 1

Percentage of webpages containing testimonials (A) or mentioning celebrities (B) or complementary and alternative medicine (C).

Figure 2

Webpages with different stance on vaccines in the entire search engine result page (A) and in the top 10 webpages (B) returned by Google. Data are expressed as percentage of websites for the entire search or number of websites in the top 10.

Figure 3

Visualization of the ranking of webpages with a negative stance on vaccines in the first 100 websites in each search engine result page (SERP). Webpages are listed in the same order they are ranked in the SERP. Yellow, vaccine-negative websites; blue vaccine-positive or -neutral. The black bar on the right indicate the top 10 webpages.

Figure 4

Vaccine stance in webpages from all search engine result page (SERPs) mentioning testimonials, celebrities, religion, or complementary and alternative medicine. Blue, vaccine-positive, gray, neutral, red, negative. * Denotes a higher frequency of vaccine-negative webpages compared to the total SERP (P < 0.05 by Fisher’s test).

Figure 5

JAMA score of webpages in the different search engine result pages (SERPs). (A) Box-and-whiskers graph indicate median, 25 and 75% percentiles, minimum and maximum. (B) Multiple comparison of different SERPs. P-values are reported only for statistically significant differences. Multiple comparison of JAMA scores among the different SERPs was performed using ANOVA followed by Kruskal–Wallis test corrected for multiplicity by controlling the false discovery rate using the method of Benjamini and Hochberg for 28 comparisons.