Suspension of proactive recommendations for HPV vaccination has led to a significant increase in HPV infection rates in young Japanese women: real-world data

Integrative literature review on human papillomavirus vaccination recommendations in national immunization programs in select areas in the Asia-Pacific region

There is limited literature on current human papillomavirus (HPV) vaccination in the Asia-Pacific region. This integrative literature review was conducted to describe HPV vaccination programs in Hong Kong, Indonesia, Japan, South Korea, Malaysia, the Philippines, Singapore, Taiwan, Thailand, and Vietnam. Program descriptions, recommendations, f unding, and coverage data were extracted. Twenty-five citations were included. As of 2022, eight of the 10 areas of interest include HPV in their national immunization program (NIP) for school-aged girls; full implementation in Indonesia is expected in 2023 whereas Vietnam's NIP does not include HPV. Singapore also includes HPV vaccination for women (18-26 years). None of the HPV vaccination programs include males. In most areas (n = 7), programs include only one vaccine option. While female HPV NIPs are present in the Asia-Pacific region, opportunities remain to strengthen NIPs in broader populations (e.g., males, catch-up cohorts) to expand public health impact and provide gender equity in HPV vaccination.

Questionnaire survey on cervical cancer screening and HPV awareness among patients at a local cancer center in Japan

BACKGROUND

The incidence of cervical intraepithelial neoplasia is increasing in Japan. Although human papillomavirus (HPV) vaccination and cancer screening are crucial in preventing cancer-related mortality, the cervical cancer screening rate in Japan was only approximately 43.6% in 2022. This study aimed to conduct an epidemiological analysis of cervical cancer by collecting data from individual patients.

METHODS

A questionnaire survey was administered to patients who visited our hospital between January 2017 and July 2023 owing to abnormal cervical cytological findings or a cancer diagnosis. Patients answered questions regarding their history of cervical cancer screening as well as their knowledge of HPV and cervical cancer.

RESULTS

During the study period, 471 patients participated in the survey, with 35 declining to participate. Patients with Stage 1b1-4b primarily sought medical attention due to self-reported symptoms (P < 0.001); however, they were less likely to have undergone cervical cancer screening (P < 0.001). Additionally, older patients were less likely to be aware of the association of HPV with cervical and other cancers. Notably, 28 of the 129 patients with stage 1b1-4b cancer underwent cervical cancer screening within 2 years. The tumor location within the endocervical canal emerged as a significant factor contributing to the difficulty for an accurate diagnosis of precancerous or cervical cancer during cervical screening. Furthermore, non- squamous cell carcinoma (SCC) histology was another possible factor.

CONCLUSIONS

Our findings suggest the need to widely disseminate information regarding the significance of cancer screening to increase cancer screening rates. Moreover, establishing strategies for improving the accuracy of detecting lesions during screening for non-SCC and endocervical canal tumors is crucial.

Human Papillomavirus Vaccination by Birth Fiscal Year in Japan

Importance

The Ministry of Health, Labour, and Welfare (MHLW) of Japan aggregates human papillomavirus (HPV) vaccination data across Japan for each fiscal year (FY) by age at vaccination. Birth FY (BFY)-specific vaccination coverage remains unknown.

Objective

To calculate the BFY-specific vaccination coverage for each FY and the cumulative first-dose coverage for each BFY in Japan, to understand the generation-specific vaccination coverage, and to estimate the cumulative first-dose coverage of each BFY that would be achieved by FY 2028 vs World Health Organization (WHO) targets.

Design, Setting, and Participants

In this cross-sectional study, MHLW-published national age-specific HPV vaccination numbers and demographic data for female individuals were used to calculate the BFY-specific first-dose coverage for each FY and the BFY-specific cumulative first-dose coverage. It was assumed that the BFYs 2007 to 2012 vaccination coverage in FY 2023 to 2028 would remain the same as the vaccination coverage of the same grade in FY 2022 to estimate the cumulative first-dose coverage that would be achieved by FY 2028. Data analysis was performed from December 2023 to January 2024.

Exposure

Two MHLW policy changes were the government's suspension of proactive recommendation for HPV vaccination in June 2013 and the government's resumption of proactive recommendation for HPV vaccination in April 2022.

Main Outcomes and Measures

The primary outcome was generation-specific vaccination coverage among female individuals born in BFYs 1994 to 2010 in FYs 2010 to 2022, calculated using reconfigured published data.

Results

In this study of vaccination data for 9 414 620 female individuals, the generation-specific vaccination coverage was 71.96% for the vaccination generation (BFYs 1994-1999), 4.62% for the vaccine-suspension generation (BFYs 2000-2003), 16.16% for the generation that received information individually (BFYs 2004-2009), and 2.83% for the vaccine-resumed generation (BFY 2010). HPV routine vaccination coverage was extremely low in BFYs 2000 to 2010 (0.84%-25.21%) vs BFYs 1994 to 1999 (53.31%-79.47%). The cumulative first-dose coverage that was estimated to be achieved in the vaccine-resumed generation by FY 2028 plateaued at 43.16%.

Conclusions and Relevance

Even after the resumption of MHLW's proactive recommendations, HPV vaccination coverage has only minimally recovered in Japan. The cumulative first-dose coverage that was estimated to be achieved in the vaccine-resumed generation by FY 2028 is below the WHO target. These findings reveal that stronger cervical cancer control measures are required, particularly for the vaccine-resumed generation, which will plateau at approximately one-half the WHO target values.

Even though active recommendation for HPV vaccination has restarted, Japan's rates have not recovered

Japan has a particularly critical situation surrounding its collapsed HPV vaccination program for preventing HPV-caused cervical cancers, a problem exacerbated by the lack of a national immunization database. We have determined the year-to-year HPV vaccination uptake by Japanese females and analyzed by birth fiscal year (FY) the monthly number of people receiving initial HPV vaccination. Our analysis covers the period from the start of public subsidies in 2010 to September 2023, using data provided by local governments. We calculated the cumulative number of monthly immunizations for those unimmunized as of April (the beginning of each vaccination year). The monthly number of initial HPV vaccinations was highest in August for every FY from FY 2010 to FY 2023; a second vaccination peak tended to occur in March when the vaccination year ended. The highest number of August vaccinations occurred in FY 2011, followed (in order) by 2012, 2021, 2022, 2023, and 2013. In Japan's ongoing catch-up vaccination program for young women, the monthly number of vaccinations increased in August 2022 but then slowed the following year. After FY 2021, the cumulative vaccination coverage of subjects unvaccinated at the beginning of the vaccination year but subsequently covered by routine immunizations was slightly improved. FY 2021 was when the governmental recommendations for HPV vaccination were resumed. More recent vaccination rates are considerably lower than those in FY 2011-2012 when vaccinations were first fully endorsed. Paralyzing HPV vaccination hesitancy, which began in FY 2013, will linger in Japan in FY 2024.

Effectiveness of catch-up and routine program of the 9-valent vaccine on cervical cancer risk reduction in Japan

In 2013, the national human papillomavirus (HPV) immunization program began. However, in June 2013, Japan's Ministry of Health, Labor and Welfare (MHLW) announced a "temporary" suspension of its recommendation for the human papillomavirus vaccine. Finally, in November 2021, the MHLW ended its suspension of the recommendation of the HPV vaccine. To address the 9-year gap in HPV vaccinations the suspension had caused, the MHLW conducted a program of catch-up vaccinations from April 2022 to March 2025. Finally, in April 2023, the 9-valent HPV vaccine was approved for both the routine and catch-up vaccination programs in Japan. In this study, we investigated the potential effects of the introduction of the 9-valent vaccine on the increased risk of cervical cancer in females born after fiscal year (FY) 2000. We estimated the lifetime relative risk of cervical cancer incidence and death using the improved routine and catch-up vaccination rates after the recent resumption of the governmental recommendation for women and girls to have the HPV vaccination. These relative risks were calculated using a lifetime risk of 1.000 for cervical cancer incidence and death for females born in FY 1993. We predicted that even if a 90% vaccination rate were to be achieved by FY 2024 with the 9-valent vaccine among women born between FY 2000 and FY 2005, the risk would remain higher than for the vaccination generation. Therefore, for women born between FY 2000 and FY 2005, it will be necessary to significantly improve the cervical cancer screening rate to compensate for this increased risk.

A comprehensive narrative review of challenges and facilitators in the implementation of various HPV vaccination program worldwide

INTRODUCTION

Cervical cancer has been considered as one of the most common cancers in women (15-44 years) globally, but the advent of the human papilloma virus (HPV) vaccine has raised the anticipation that eradication of cervical carcinoma might be achieved in the near future as several prophylactic cervical carcinoma vaccines have already been currently licensed in various countries. Countries should devise strategies, practices and policies to attain and sustain higher levels of HPV immunization coverage as still 68% countries have introduced HPV vaccine in their national immunization programs even after 17 years following the licensure of the first prophylactic HPV vaccine.

METHODOLOGY

A comprehensive literature analysis was conducted using various databases and search engines, to include the most relevant research articles and data available and critically discussed the operational gaps that need to be answered to achieve adequate coverage of HPV vaccination.

RESULTS

The present review highlights the existing HPV vaccination strategies, unmet needs and challenges needed to be addressed for proper implementation framework as well as the collaborations required to achieve decent vaccination coverage. Well-coordinated vaccination strategy with focus on adolescent girls and if possible, boys can lead to dramatic impact on disease reduction around the world.

Intentions for catch-up HPV vaccination in Japan: an internet survey

PURPOSE

In Japan, Japan's Ministry of Health, Labor, and Welfare decided to suspend govermental recommendation for HPV vaccination in FY 2013. The HPV vaccination rate for those born in FY 2000 or thereafter declined dramatically. In 2021, the "suspension of recommendation" ended. The catch-up vaccinations for the unvaccinated have been offered nationwide from FY 2022 to FY 2024. We aimed to quantify the vaccination intentions and characteristics of those young women now eligible for catch-up vaccination.  METHODS: In February of 2022, we conducted an internet survey targeted women who were born in 1997-2004 but who had not yet been HPV vaccinated.

RESULTS

We received 1,648 valid responses. 41.6% of the respondents wanted to uptake the catch-up HPV vaccination, 29.7% were undecided, and 28.7% did not want to be vaccinated. The intention to uptake catch-up HPV vaccination was associated with a good history of gynecological visits, intention to receive cervical cancer screening, sexual activity, degree of anxiety about cervical cancer, familiarity with problems associated with cervical cancer, experience with vaccination recommendations, and knowledge about cervical cancer (p < 0.05, respectively). In the vaccinated generation, the proportion of the group that did not want to be vaccinated was significantly higher (p < 0.05). In the vaccine-suspended generation, the proportion of the group that wanted to be vaccinated was significantly higher (p < 0.05).

CONCLUSION

Our survey revealed that catch-up vaccination intentions differed depending on the vaccination environment. It is necessary for all organizations involved with HPV vaccination, such as government, medical institutions, and educational institutions, to make recommendations based on an understanding of the characteristics of the "vaccinated generation" and the "vaccine-suspended generation".

Etiology, diagnosis, treatment, and prevention of human papilloma virus-associated oropharyngeal squamous cell carcinoma

Classical oropharyngeal squamous cell carcinoma (OPSCC) caused by alcohol consumption and smoking and HPV-associated OPSCC caused by human papillomavirus (HPV) infection have different etiologies, incidences, and prognoses. Therefore, the 8th American Joint committee on Cancer (AJCC) and Union for International Cancer Control (UICC) TNM classifications propose distinguishing HPV-associated OPSCC from classical OPSCC and classifying it as an independent disease. Therefore, this review provides an overview of HPV-associated OPSCC from the perspectives of epidemiology, carcinogenesis, development, diagnosis, treatment, and prevention. The incidence of HPV-associated OPSCC is increasing. Although HPV vaccination has been shown to be effective at reducing the incidence of cervical cancer, it is still unclear how it affects the incidence of HPV-associated OPSCC. Additionally, the prognosis of patients with HPV-associated OPSCC is extremely favorable compared to that of patients with classical OPSCC. Therefore, patients with HPV-associated OPSCC may undergo reduced-dose therapy, although attempts to reduce treatment intensity should be carefully planned to ensure they do not compromise oncological outcomes, and large-scale trials aimed at reducing treatment intensity are ongoing.

Disparities among Japanese municipalities in recommendations for routine and catch-up HPV vaccinations

In November 2021, the government of Japan announced a reversal of its decision in 2013 to suspend the previous proactive recommendation for HPV vaccination. However, the program for young girls to receive routine and catch-up vaccinations has not necessarily developed as expected. We conducted a nationwide questionnaire survey by mail in September 2022. The survey was mailed to 133 municipalities consisting of all cities/wards of the Tokyo and Osaka Prefectures and all other prefectural capital cities. Responses were received from 82 municipalities (62.7%). Notification of routine HPV vaccinations had already been sent to 76 (92.7%) of the municipalities; 70 (85.4%) had been encouraged to promote catch-up vaccinations. The questionnaire forms for registration and pre-vaccination screening for routine immunization had been sent to 74.1% (60/81) of the municipalities and 68.8% (55/80) for catch-up immunizations. For catch-up vaccination, only 54 municipalities (65.9%) had detailed vaccination records for those eligible. In total, 10 municipalities (12.2%) had virtually no vaccination records because these had already been discarded. In addition, 61 municipalities (74.4%) had notified only women and girls eligible for a catch-up vaccination based on their vaccination record, whereas 25.6% (21/82) of the municipalities reported that they had sent, or would send, the notification to all women and girls within the targeted grades, including those who had already been vaccinated with three injections. The survey revealed disparities among the municipalities in their HPV vaccine notification processes. Future research on monitoring HPV vaccination rates and incidence rates of cervical cancer and precancerous lesions in each municipality will be desirable.

Updates on HPV Vaccination

Cervical cancer still poses a significant global challenge. Developed countries have mitigated this challenge by the introduction of structured screening programmes and, more recently, the HPV vaccine. Countries that have successfully introduced national HPV vaccination programmes are on course for cervical cancer elimination in a few decades. In developing countries that lack structured screening and HPV vaccination programmes, cervical cancer remains a major cause of morbidity and mortality. The HPV vaccine is key to addressing the disproportionate distribution of cervical cancer incidence, with much to be gained from increasing vaccine coverage and uptake globally. This review covers the history and science of the HPV vaccine, its efficacy, effectiveness and safety, and some of the considerations and challenges posed to the achievement of global HPV vaccination coverage and the consequent elimination of cervical cancer.

Health impact and cost effectiveness of implementing gender-neutral HPV vaccination in Japan

OBJECTIVE

To assess the public health impact and cost effectiveness of gender-neutral vaccination (GNV) versus female-only vaccination (FOV) with human papillomavirus (HPV) vaccination in Japan.

METHODS

We modeled the public health impact and cost effectiveness of GNV versus FOV to prevent HPV-associated diseases in Japan over the next 100 years. We used one-way sensitivity analyses to examine the impact of varying key model input parameters and conducted scenario analyses to explore the effects of varying the vaccination coverage rate (VCR) of each cohort.

RESULTS

In the base-case analysis, GNV averted additional cancer cases (17,228 female/6,033 male) and deaths (1,892 female/1,849 male) compared to FOV. When all HPV-associated diseases were considered, GNV had an incremental cost-effectiveness ratio of ¥4,732,320 (US$35,987)/quality-adjusted life year gained compared to FOV. The model was most sensitive to the discount rate and the disutility associated with HPV-related diseases. GNV had greater relative public health benefits when the female VCR was lower and was cost effective at a female VCR of 30%.

CONCLUSIONS

Immediate implementation of GNV would reduce the disease burden and mortality associated with HPV in Japan, and would be cost effective compared to FOV if the female VCR remains low (30%).

Can Catch-Up Vaccinations Fill the Void Left by Suspension of the Governmental Recommendation of HPV Vaccine in Japan?

In 2013, the Ministry of Health, Labor, and Welfare (MHLW) in Japan announced a suspension of the governmental recommendation for routine HPV vaccinations. In 2020, MHLW started individual notifications of HPV vaccine to the targeted girls. In April 2022, the governmental recommendation was restarted, and catch-up vaccinations started. We evaluated the benefits and limitations of the MHLW's new vaccination strategies by estimating the lifetime risk for cervical cancer for each birth FY under different scenarios to suggest a measure for the vaccine suspension generation. It was revealed that catch-up immunization coverage among the unvaccinated must reach as high as 90% in FY2022, when the program begins, in order to reduce the risk of the females already over the targeted ages to the same level or lower than that of women born in FY1994-1999 who had high HPV vaccination rates. For women whose vaccination coverage waned because of their birth FYs, strong recommendations for cervical cancer screening should be implemented.

Change of HPV vaccination rates in Japan: the effect of individual notifications implemented by local governments

BACKGROUND

In Japan, in June 2013, The Ministry of Health, Labor and Welfare (MHLW) decided to temporarily suspend its official recommendation for the participation of girls in the national immunization program. The HPV vaccination rate in Japan soon declined to below 1%. In October 2020, the MHLW notified that the municipalities could and should begin to individually notify girls and their parents targeted for routine vaccination. We have examined how that type of individual notification has affected the number of vaccinations.

METHODS

From 12 municipalities (with a combined total population of approximately 4.06 million), we collected vaccination data for all girls who attended grades 6 through 10 from April 2019 to March 2021. We analyzed the number of initial-round vaccinations that occurred by month and the timing and the subjects of the individual notifications.

RESULTS

The annual vaccination rate for tenth-grade students in 2020 in the six municipalities that had implemented individual notification was 9.46% (342/3618), which was significantly higher than the rate of 3.22% (54/1676) in the three municipalities that had not implemented individual notification (p < 0.001). On the other hand, the annual vaccination rate for the sixth to ninth-grade students in 2020 in the six municipalities that had implemented individual notification was not significantly (p = 0.56) higher than the rate in the three municipalities that did not: 1.43% (197/13,785) versus 1.33% (83/6260), respectively.

CONCLUSION

This study clearly demonstrates the importance of providing information for routine vaccination directly to the targets and their parents.

Effectiveness of HPV vaccine against cervical precancer in Japan: multivariate analyses adjusted for sexual activity

Japanese girls aged 12–16 years are offered free human papillomavirus (HPV) vaccination and cervical cancer screening is conducted with cytology and not HPV testing from the age of 20 years. So far, no study has analyzed the effect of HPV vaccination against cervical precancers considering HPV infection status and sexual activity. We aimed to analyze the vaccine effectiveness (VE) against HPV infection and cytological abnormalities, adjusted for sexual activity. This study comprised women aged 20–26 years who underwent cervical screening in Niigata. We obtained HPV vaccination status from municipal records and a questionnaire along with information concerning sexual activity. Of 5194 women registered for this study, final analyses included 3167 women in the vaccinated group (2821 vaccinated women prior to sexual debut) and 1386 women in the unvaccinated group. HPV 16/18 (0.2% vs 3.5%), 31/45/52 (3.4% vs 6.6%), and 31/33/45/52/58 (5.0% vs 9.3%) positive rates were significantly lower in the vaccinated group (P < 0.001). No women vaccinated before sexual debut had HPV 16/18‐related cytological abnormalities. VE for HPV 16/18 infection and high‐grade cytological abnormalities in women vaccinated prior to sexual debut were 95.8% (95% CI 81.9–99.0%; P < 0.001) and 78.3% (95% CI 11.3–94.7%; P = 0.033), respectively, in multivariate analyses adjusted for age and number of sexual partners. However, analyses of all vaccinated women did not show significant effectiveness against cytological abnormalities. Our results showed the effectiveness of HPV vaccine against high‐grade cervical cytological abnormalities and the importance of the vaccination before sexual debut.