Newspaper coverage before and after the HPV vaccination crisis began in Japan: a text mining analysis

The human papillomavirus (HPV) vaccination coverage rate has fallen sharply in Japan since 2013, when newspapers began covering negative campaigns against the vaccination. We examined and compared contents from newspaper articles before and after the start of this HPV vaccination crisis.

We collected articles published between January 2005 and September 2017 in the four daily national Japanese newspapers with the highest domestic circulation. We then conducted text mining analysis to chronologically examine content distribution.

From among the 1178 articles analyzed, 12 types of contents were identified. Contents related to cervical cancer prevention, such as on the risk of developing cervical cancer, causes of cervical cancer, and the effects of vaccination, were frequently conveyed until 2012. However, after March 2013, they were replaced with anti-vaccination contents, such as on adverse effects to vaccines, alleged victims, and related lawsuits. Meanwhile pro-vaccination contents, such as safety statements from the World Health Organization, scarcely received coverage.

Newspaper contents changed profoundly before and after the start of the vaccination crisis. Those newspaper reports potentially had impact on readers' beliefs and actions. Journalists should strive for impartial coverage so readers can make more-informed decisions. Health professionals should be expected to work with journalists to help improve impartiality in newspaper coverage. The Ministry of Health, Labour and Welfare should discus benefits and risks of the HPV vaccination based on the scientific evidences, and consider to resume the proactive recommendation of HPV vaccination. Well-organized advocacy among medical societies, scientists and health professionals will also be needed to influence the government.