Realistic fear of cervical cancer risk in Japan depending on birth year

Abstract

Objective: In Japan, the possible adverse events upon HPV vaccination was widely reported in the media. MHLW announced the suspension of aggressively encouraging HPV vaccination in 2013, and inoculation rate has sharply declined. The aim of the present study was estimation of future cervical cancer risk.Methods: The latest data on vaccination rate at each age in Sakai City were first investigated. The rate of experiencing sexual intercourse at the age of 12, 13, 14, 15, 16, 17 and throughout lifetime is assumed to be 0%, 1%, 2%, 5%, 15%, 25%, and 85% respectively. The cervical cancer risk was regarded to be proportional to the relative risk of HPV infection over the lifetime. The risk in those born in 1993 whom HPV vaccination was not available yet for was defined to be 1.0000.Results: The cumulative vaccination rates were 65.8% in those born in 1994, 72.7% in 1995, 72.8% in 1996, 75.7% in 1997, 75.0% in 1998, 66.8% in 1999, 4.1% in 2000, 1.5% in 2001, 0.1% in 2002, and 0.1% in 2003. The relative cervical cancer risk in those born in 1994–1999 was reduced to 0.56–0.70, however, the rate in those born in 2000–2003 was 0.98–1.0, almost the same risk as before introduction of the vaccine.Discussion: The cumulative initial vaccination rates were different by the year of birth. It is confirmed that the risk of future cervical cancer differs in accordance with the year of birth. For these females, cervical cancer screening should be recommended more strongly.

Reduction in HPV16/18 prevalence among young women with high‐grade cervical lesions following the Japanese HPV vaccination program

“…The coverage of HPV vaccines in Sapporo (Hokkaido, Japan) was high (70% for 3‐dose completion) in female individuals born between 1994 and 1998, 30%‐40% in those born in 1999, but very low (less than 1%) in those born in 2000 or later . A similar decrease in HPV vaccine coverage was reported in Sakai (Osaka, Japan) . Suspension of the recommendation for vaccination has continued to the present, despite no scientific or epidemiologic evidence showing a causal link between postvaccination symptoms and HPV vaccines .…”

“…Therefore, the age range of women who benefit from catch‐up vaccination might be country‐specific. The effectiveness of catch‐up vaccination for women older than 21 years is one of the most important issues in HPV vaccination, especially in Japan, because the vaccination rate in women born in or after 2000 is extremely low (less than 1%) . Therefore, additional studies will be warranted to confirm the limited effectiveness of catch‐up vaccination in women older than 20 years.…”

Safety and Immunogenicity of the Quadrivalent HPV Vaccine in Japanese Boys: a Phase 3, Open-Label Study

“…Additionally, WHO reported that genderneutral vaccinations may be cost-effective if the HPV vaccination coverage in girls is ＜ 50 (23). In Japan, HPV vaccination rates are low, with a cumulative vaccination rate of 0.1 reported in those born in 2003 (30). If the vaccination rate continues to remain low in females, it will be important for males to receive the qHPV vaccine to prevent the spread of HPV-related disease, as male vaccination may contribute to herd immunity (9,17), which has the potential to reduce the spread of HPV infection in both genders.…”

HPV vaccination in Japan: results of a 3-year follow-up survey of obstetricians and gynecologists regarding their opinions toward the vaccine.

“…Even now mothers are hesitating to recommend inoculation with HPV vaccine to their daughters because of the suspension of the governmental recommendation. At first mothers required a restart of the recommendation, and next they want see girls of a similar age as their daughter get safely vaccinated before they will encourage their own daughter to get vaccinated [11]. Creating a significant and positive change in the The GACVS has systematically investigated safety concerns raised about HPV vaccines and has issued several reports in this regard.…”