November 30, 2015 — Websites with incorrect or incomplete information on the human papillomavirus vaccine are often highly ranked in Web searches, which can make it difficult for people to find accurate data on the vaccine, according to a new study published in the Journal of Adolescent Health, Reuters reports (Rapaport, Reuters, 11/27).
Background on Vaccine
The HPV vaccine protects against several strains of the virus, which can lead to cervical, anal, penile and throat cancers. The first vaccine became available in 2006. Shortly thereafter, CDC's Advisory Committee on Immunization Practices recommended vaccination for all children ages 11 or 12.
Rhode Island, Virginia and Washington, D.C., require children to receive the vaccine (Women's Health Policy Report, 11/24).
For the study, researchers performed 20 different Google searches for details on the HPV vaccine and found 116 unique Web pages (Reuters, 11/27).
They varied the terminology used in their searches and evaluated the resulting Web pages based on disclosure of authors and sources, attribution of references, how recent the information was, whether the websites included anecdotal testimonials, and the websites' reading level. The researchers also gauged how comprehensive the websites were by examining how many of 14 HPV-related topics the websites mentioned.
The researchers found that when they conducted online searches for the HPV vaccine, about one-third of the top five to 10 search results were "vaccine-critical Web pages" (Fu et al., Journal of Adolescent Health, 11/7).
According to the study, 39% of the Web pages presented data on the HPV vaccine in a negative light, including claims about fatality risks, severe side effects, insufficient research and concerns that the vaccine encourages sexual activity. Linda Fu, lead author and pediatrician at Children's National Health System and George Washington University, said, "In general, web pages that were against rather than neutral or supportive of HPV vaccination were of lower quality and had less complete information."
The study found that searches that included negative terms like "dangers" or "risks" yielded more top results that framed the HPV vaccine negatively compared with searches that used neutral terms such as "HPV vaccine" or "cervical cancer vaccine."
The researchers also found that while a majority of websites mentioned cervical cancer, information on other diseases related to HPV -- including genital and anal tumors, head and neck cancers or genital warts -- was omitted in more than half of the websites. These other diseases were more likely to be mentioned on websites that were not critical of the vaccine.
In addition, although about 50% of the websites specified who should receive the vaccine, fewer sites provided information on the cost of the vaccine or how to acquire it.
The researchers said they did not have data on the most common terms used by individuals searching for HPV vaccine information. However, they noted that people who were more skeptical of the vaccine may use negative search terms and find results that would reaffirm their beliefs.
Fu said, "When web pages with inaccurate or incomplete medical information are ranked highly by search engines, there's a greater chance that more people are going to view them, which means they will stay highly ranked and continue to perpetuate misinformation."
Vetta Sanders Thompson -- a researcher at Washington University in St. Louis, who was not one of the study authors -- said the study affirmed that people with questions about the vaccine should ask their health care providers directly. "Individuals with a usual source of care and a relationship with a physician may have fewer questions and concerns and we know that they have less uncertainty about the vaccine," she said (Reuters, 11/27).