Figure 1.

Google relative search volume trends (RSV) in the United States for the HPV, hepatitis B, varicella, and meningococcal conjugate vaccines from 2004 through 2015. 0 = average volume of search; 100 = 100 × average volume of search. RSV data were downloaded from Google Trends (www.google.com/trends). Weekly search data for the United States were retrieved using the terms “hpv vaccine,” “hepatitis b vaccine,” “varicella vaccine,” and “meningitis vaccine” from January 4, 2004 (the first date data are available) until September 19, 2015 (the last full week prior to manuscript preparation).