Newspaper Coverage Before and After the HPV Vaccination Crisis Began in Japan: A Text Mining Analysis

"Media coverage of vaccination issues can affect parents' decision making on having their children vaccinated, and can consequently affect vaccine uptake."

Studies show that limited knowledge about human papillomavirus (HPV) infection, HPV vaccines, and cervical cancer, as well as concerns regarding the safety of HPV vaccines, are among factors associated with parents' and daughters' hesitant attitudes toward HPV vaccines inside and outside Japan. This study used a text mining method to quantitatively examine contents of Japanese newspaper articles about HPV vaccination before and after a crisis that began in March 2013. It also presents a discussion of potential impact that those newspaper reports may have had on readers, making some recommendations for journalists, going forward.

The HPV vaccination rate for girls aged 12-16 years was as high as about 70% in 2011 and 2012 in Japan. However, in March 2013, The Asahi Shimbun, considered to be an authoritative newspaper, reported on a girl who had allegedly suffered from severe adverse effects attributed to the HPV vaccine. Newspapers, television, and other media followed suit, and continuously reported on adverse events of HPV vaccination, including movement disorders and memory disturbances. Although HPV vaccines became a routine prophylactic vaccine under Japan's Preventive Vaccination Law in April 2013, the Japanese government decided to suspended its proactive recommendation of HPV vaccination in June 2013, in consideration of public concerns about those adverse events. As a result, the HPV vaccination rate fell sharply, to only a few percent by 2014.

The researchers collected articles published between January 2005 and September 2017 in the 4 daily national Japanese newspapers with the highest domestic circulation in Japan, totaling about 20 million: The Asahi Shimbun, The Yomiuri Shimbun, The Mainichi Shimbun, and The Nikkei. They then conducted text mining analysis to chronologically examine content distribution.

During the time frame analysed, there were 4 peaks of number of articles and paragraphs: around November 2010, at the start of public subsidies for HPV vaccination; in April-June 2013, with continuous media reports about severe adverse effects of HPV vaccination, start of free HPV vaccination based on the public expenditure system, and suspension of the government's proactive recommendation of HPV vaccination; around September 2015, when the government decided to pay medical expenses to those who suffered from adverse effects; and around July 2016, when individuals who suffered from adverse effects filed lawsuits. The number of articles and paragraphs decreased in 2017, which may reflect journalists' decreasing interest and may indicate the general public will in the near future to forget HPV vaccination as a past scandal, despite this being the first case of strong vaccine hesitancy in Japan driven by safety concerns.

From among the 1,178 articles analysed, 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 (WHO), barely received coverage. For instance, the WHO's Global Advisory Committee of Vaccine Safety (GACVS) criticised the shift in Japan's HPV vaccine policy in March 2014, stating that "policy decisions based on weak evidence, leading to lack of use of safe and effective vaccines, can result in real harm". The GACVS also reaffirmed this opinion in December 2015, stating that "young women are being left vulnerable to HPV-related cancers that otherwise could be prevented". However, among the examined newspapers, these opinions from the WHO were scarcely conveyed to Japanese public. This may have contributed to readers' avoidance of the vaccines, considering that a lack of health professionals' recommendations is associated with hesitancy toward the vaccines.

In short, newspaper contents changed profoundly before and after the start of the vaccination crisis. Those newspaper reports potentially had impact on readers' beliefs and actions. In part, this is because dominant frames of media coverage often define what issues audiences view as important. Studies have reported that Japanese mothers, who are the main decision-makers in relation to the HPV vaccination for their daughters, underestimate the morbidity and mortality associated with cervical cancer and overestimate the probability of severe adverse effects 10- to 1,000-fold. Newspaper articles focusing on the adverse effects of HPV vaccines after March 2013 may have helped define the audience's views and contributed to formation of false perceptions regarding the vaccines. (In part, this is due to the language some articles used. Descriptive language such as "the symptoms may be adverse side effects of HPV vaccines" is neutral, whereas "damage" and "victims" strongly suggest a causal relationship between vaccination and subsequent symptoms. Articles using such terms likely stoked readers' fears.) Studies show that concern about adverse effects is a strong barrier to HPV vaccination; articles focused on adverse effects may have encouraged readers to forgo vaccination.

The researchers suggest that journalists should strive for impartial coverage so readers can make more-informed decisions. They can be aided in this by health professionals, who are advised to work proactively with journalists to facilitate unbiased and balanced newspaper coverage. For example, Japanese health professionals could more hold press conferences and study meetings about HPV vaccination with journalists to build relationships with them, cultivate specialists, and provide resources. In addition, increasing the number of health professionals who have direct and unfiltered input into issues via outlets such as blogging and Twitter may help them promote and advocate for HPV vaccination.

Furthermore, the researchers assert that the Ministry of Health, Labour and Welfare should discuss benefits and risks of the HPV vaccination based on scientific evidence and consider resuming the proactive recommendation of HPV vaccination - emphasising safety more strongly and responding robustly to misinformation. Well-organised advocacy among medical societies, scientists, and health professionals will also be needed to influence the government.

In conclusion: "Future research should continue to monitor newspaper coverage of HPV vaccines to assess this [newspaper] coverage for bias."