In Japan, the serious adverse events after human papillomavirus (HPV) vaccination were widely reported in the media. The Ministry of Health, Labour and Welfare of Japan (MHLW) announced the suspension of the governmental recommendation of HPV vaccine in 2013, and the inoculation rate has since sharply declined. The estimated inoculation rate for each birth fiscal year (FY) announced by the MHLW and the actual numbers for each birth FY surveyed by local governments were very different. In particular, the cumulative vaccination rate of girls born in FY2000 was regarded to be as high as 42.9% by the Council of the MHLW. However, this estimation included a confusion. When the suspension of the governmental recommendation was announced in FY2013, the girls born in FY2000 turned 13 years old, the targeted starting age of the HPV vaccination. The vaccination rate of this generation is considered to be quite low. The numbers were recalculated in this study. This study revealed that the real vaccination rate is only 14.3%. Female individuals born in or after FY2000 have been confirmed to be exposed to the same cervical cancer risk as before the HPV vaccine was introduced in Japan.

Cervical cancer remains among the most common cancers in women worldwide and can be prevented by vaccination. The Ministry of Health, Labour and Welfare of Japan suspended active recommendation of regular human papillomavirus (HPV) vaccines in 2013 because of various symptoms including chronic pain and motor impairment. This nationwide case‐control study from April 2013 to March 2017 targeted women aged 20‐24 years old at cervical screening. We compared HPV vaccination exposure between those with abnormal and normal cytology. Abnormal cytology was classified based on the results of histological test and we calculated the odds ratio (OR) and 95% confidence interval (CI) of the above endpoints and vaccination exposure using the conditional logistic regression model and estimated vaccine effectiveness using the formula (1 – OR) × 100. A total of 2483 cases and 12 296 controls (one‐to‐five matching) were eligible in 31 municipalities in Japan. The distribution of histological abnormalities among cases was 797 CIN1 (including dysplasia) (32.1%), 165 CIN2 (6.7%), 44 CIN3 (1.8%), and eight squamous cell carcinoma (SCC) (0.3%). The OR of HPV vaccination compared with no vaccination for abnormal cytology, CIN1+, CIN2+, and CIN3+ versus controls was 0.42 (95% CI, 0.34‐0.50), 0.42 (95% CI, 0.31‐0.58), 0.25 (95% CI, 0.12‐0.54), and 0.19 (95% CI, 0.03‐1.15), respectively, equating to a vaccine effectiveness of 58.5%, 57.9%, 74.8%, and 80.9%, respectively. Eight patients had SCC, none was vaccinated. This nationwide case‐control study in Japan demonstrated a substantial risk reduction in abnormal cytology and CIN among women who did versus those who did not receive HPV vaccination.

The Japanese government suspended proactive recommendations for the HPV vaccine in June 2013. The suspension is now in its seventh year, despite all the data pointing to the safety of the HPV vaccine. We reported a high vaccine effectiveness in the group of women vaccinated before their first intercourse (93.9%). The prevalence of cross-protected types of HPV 31/45/52 was also lower in the vaccinated group, and the vaccine effectiveness was 67.7%. Furthermore, prevalence of HPV16, 31 and 52 infection rates in the vaccinated group were obviously lower than that in the unvaccinated group, and no one had HPV18 or 45 infection in the vaccinated group. The addition of a cross-protective effect toward HPV types 31/45/52 to HPV types 16/18, which is the direct target of the bivalent HPV vaccine, may possibly prevent around 82% of invasive cervical cancer cases in Japan. With regard to the preventive effect of histological abnormalities, we also reported significant reduction in incidence of cervical intraepithelial neoplasia (CIN)3 or worse. Thus, the efficacy of the vaccine has been demonstrated for precancerous disease, and the diverse symptoms after HPV vaccination are likely functional somatic. For the future of Japanese girls, there is a need to resume the proactive recommendation of HPV vaccination and for immediate action to be taken by the Japanese government.

In Japan, new HPV immunizations have dropped dramatically after repeated adverse media reports and a June 2013 temporary suspension of the government’s recommendation for the vaccine. The aim of the present study was to develop an efficient strategy to improve HPV immunization coverage across Japan. We conducted an internet survey in Japan of mothers of 12–16 year-old girls who were unvaccinated as of May, 2015. The goal was to gather behavioral information from the mothers to develop a strategy for improving Japanese HPV immunization coverage. Valid survey answers were obtained from 2060 mothers. The survey found that a hypothetical restart of a governmental recommendation for the vaccine would induce 4.1 % of all the mothers surveyed to be more likely to encourage vaccination of their daughters, without any other preconditions. This initial result would be followed by a moderate spread of vaccinations to these daughters’ close friends and acquaintances, hypothetically resulting in a total vaccination rate of 21.0 % of the targeted age-eligible girls. As a second critical step for improving vaccinations, an educational information sheet integrating the concepts of behavioral economics for changing behaviors was found to be significantly effective for persuading mothers with poorer decision-making facilities, who would otherwise prefer to wait to first see the vaccination of other girls of the same age as their daughter. Following what we foresee as the inevitable restart of the Japanese government’s recommendation for receiving the HPV vaccine, we expect to first see vaccinations occurring in a very small group of girls, the daughters of the most willing mothers, which will be roughly 4 % of those eligible for government paid vaccinations. This will be followed by the spread of vaccinations outward through these girls’ circle of friends and acquaintances, and, finally, to the daughters of the most skeptical mothers, those who would await the return of new vaccine safety results from a large group of similarly-aged girls. As a critical step in improving HPV vaccine coverage in Japan, an educational information sheet that integrates the concepts of behavioral economics for changing behaviors can be employed to persuade mothers with poor decision-making facilities.

In Japan, government subsidies for human papillomavirus (HPV) vaccination of girls aged 13–16 commenced in 2010. By early 2013, vaccination had become a widely accepted national immunization program. However, in June of 2013, the Ministry of Health, Labor, and Welfare (MHLW), the government’s lead agency, suspended its recommendation for vaccination in response to reports of adverse vaccine events. The rate of HPV vaccination quickly dropped from 70% to almost zero, where it has lingered for eight years. In 2020, a new 9-valent HPV vaccine was licensed in Japan. The momentum seemed to be building for the resumption of HPV vaccinations, yet Japanese mothers remain widely hesitant about vaccinating their daughters, despite the well-proven safety and efficacy of the HPV vaccines. The Japanese government and our educational and medical institutions must work harder as a team to inform our parents and their children about the life-saving benefits of the HPV vaccine, and at the same time, we must respond to all their concerns and questions. The vaccine hesitancy of unvaccinated women born in 2000 and thereafter is a natural consequence of the suspension of the government‘s recommendation. We must also take every possible measure to reduce the significant risk for cervical cancer these women have.