Suchergebnisse

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.

Japan's governmental recommendation of HPV vaccine has now been suspended for more than 4 years. In and before 2013, the targets of 20-year-old cervical cancer screening were females born in and before 1993, i.e., those who could not have received HPV vaccination because it was not yet publicly introduced. The targets during 2014–2019 are, or will be, those born in 1994–1999, i.e., those who came of age during a period with the highest HPV immunization rate. We analyzed the statistical data for each birth year, for the cumulative HPV vaccination rates achieved as of age 16, and for the corresponding results of cervical cancer screening at age 20. The rate of abnormal findings in cervical cytology increased slightly from 3.68% in 2010 (birth year: 1990) to 4.35% in 2013 (birth year: 1993); however, it dynamically dropped to 2.99% in 2014 (birth year: 1994) and 3.03% in 2015 (birth year: 1995). In total, the rate of abnormal findings in cervical cytology was 3.96% in 2010–2013, but significantly dropped to 3.01% in 2014–2015 (p = 0.014). This is the first description of dynamic changes occurring in the abnormal rate of cervical cancer screening as a result of positive changes in national HPV vaccination rates.

In 2013, recurrent reports of diverse symptoms occurring in girls after receiving HPV vaccination appeared in Japanese media. The Ministry of Health, Labor and Welfare quickly responded by announcing a temporary suspension of its recommendation for the vaccine. The HPV vaccination rate soon fell to almost zero. In the present study, we calculated the potential future numbers of cervical cancer incidence and death that will be increased by this policy decision. We have assumed that the number of yearly vaccinations is evenly distributed across a daily basis. Future incidence and death increased in females born in FY2000 are estimated to be 3651 and 904, respectively, 4566 and 1130 for those born in FY2001, 4645 and 1150 for those born in FY2002, and 4657 and 1153 for those born in FY2003. In FY2020, the large increase of risks to females born in FY2004 amounts to 12.0 females per day who will now be at a higher risk for acquiring of cervical cancer in their future, and 3.0 females per day newly at risk for future death from that disease in its progressive form. No one should be able to accept this situation. We sincerely ask the government to resume its recommendation for the vaccine as soon as possible.

The trend for cervical cancer in younger women has been increasing recently in Japan. However, as a result of the suspension of governmental recommendation, Japan's HPV (human papillomavirus) vaccination rate for girls born since 2000 has dropped sharply. We conducted an internet survey in December of 2019, 76 months after the suspension of recommendation, to verify the intention of mothers to inoculate their daughter under current circumstances and compared with our previous surveys and leaflet intervention effect. The rates of mothers who replied that they would "inoculate" were significantly higher at 9 and 23 months, but by 32 months after the suspension the rate was significantly lower (p < 0.05, p < 0.05, p < 0.05, respectively). The rates of the mothers who replied they would not inoculate were significantly lower at 9 months and 23 months, but at 76 months was significantly higher (p < 0.05, p < 0.05, p < 0.05, respectively). We found that intervention with a leaflet that could be used under the current suspension of the governmental recommendation did not increase the mothers' intention to inoculate their daughters. A leaflet that actively encourages vaccination may increase the intent of vaccination. It is strongly recommended that the MHLW promptly resume its recommendations for HPV vaccination.

Organized human papillomavirus vaccination (OHPV) in Japan was introduced in 2010 for girls aged 12–16 years who were born in 1994 or later. The rate of OHPV coverage was 70–80%. However, after suspension of the government vaccination recommendation, the coverage dramatically decreased. We aim to investigate the change in prevalence of HPV infection after the initiation of HPV vaccination. We recruited females aged 20–21 years attending public cervical cancer screening from 2014 to 2017 fiscal years (April 2014 to March 2018). Residual Pap test specimens were collected for HPV testing. We compared the prevalence of HPV type-specific infection between women registered in 2014 (born in 1993–1994, including the pre-OHPV generation) and registered in 2015–2017 (born in 1994–1997, the OHPV generation). We collected 2379 specimens. The vaccination coverage figures were 30.7%, 86.6%, 88.4% and 93.7% (p < 0.01) from 2014 to 2017, respectively. The prevalence of HPV16/18 infection significantly decreased from 1.3% in 2014 to 0% in 2017 (p = 0.02). The three most prevalent types were HPV52, 16 and 56 in 2014, and HPV52, 58 and 56 in 2015–2017, respectively. HPV16 and 33 infection rates decreased. On the other hand, the HPV58 infection rate was obviously increased after OHPV from 0.3% to 2.1%. Our study demonstrates that the prevalence of HPV16/18 infection dramatically decreased and the profile of type-specific HPV infection was changed after OHPV.

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, the trend for cervical cancer at younger ages has been increasing. As a countermeasure, the HPV vaccine was introduced as a routine vaccination in April 2013. However, the Ministry of Health, Labour and Welfare (MHLW) announced a "Suspension of its active inoculation recommendation for HPV vaccine" in June 2013. In 2016, 32 months after that suspension, we conducted survey via Internet and compared the results with our previous ones conducted at 9 and 23 months after suspension (in 2014 and 2015, respectively). We examined the 'time-dependent change' of the 'intention of mothers to inoculate their daughters with the HPV vaccine' in terms of efficacy of external decision-making support. 17.5% of mothers in the first survey replied that they would inoculate their daughters under the current circumstances, 12.1% in the second survey, and 6.7% in the third, showing a consistent decrease in willingness over time (p = 0.03, p < 0.01). If the government recommendation were to be reintroduced, 22.5% of mothers in the first survey replied they would inoculate their daughters, 21.0% in the second survey, which indicated no significant difference (p = 0.65) over the first interval; however, this was significantly decreased to 12.2% in the third survey (p < 0.01). Our study revealed that the intention to inoculate their daughters has been declining among Japanese mothers over time triggered by the suspension.