Papillomavirus Vaccines clinical trials

Changes in the Prevalence of Oncogenic HPV Types

In Japan, nationwide prophylactic HPV vaccination was implemented in 2010; a bivalent vaccine was given from 2010 to 2012, and a quadrivalent vaccine from 2012. However, the program essentially ceased in June 2013. 1. Our first objective is to examine the prevalence of 6, 11, 16, 18, 31, 33, 45, 52, and 58 targeted by the nonavalent HPV vaccine in young Japanese women, and identify changes in the prevalence of these HPV types from 2011- 2012 (as reported in JHERS-2016; Sasagawa T, J Med Virol, 2016) to the present time (2020-2021). Especially, the investigators will focus on the prevalence of HPV16 and 18 in women aged 21-26 years and compare these data to those of the previous study. 2. The investigators will assess the prevalence of HPV16 and 18 in women aged 16-18 years and compare these data to those of the HPV vaccine era (2010-2013). 3. The investigators will explore the prevalence of other high-risk HPV types (35, 39, 51, 56, 59, and 68), 11 probable high-risk types (26, 30,34, 53, 66, 67, 69, 70, 73, 82, and 85), and SILs in Japanese young women, since these types might be causative HPV types for cervical cancer in the future after world-wide HPV vaccination. Currently, it is unclear whether HPV vaccination has reduced the prevalence of HPV16 and 18 in Japan. Our previous study (JHERS-2016; performed during 2011-2012; Sasagawa T, J Med Virol, 2016), the only population-based study on HPV prevalence at the commencement of prophylactic HPV vaccination in Japan, included prevalence data for HPV types 6, 11, 16, and 18 and the associated cervical abnormalities. The investigators hypothesize that the prevalence of HPV16 and 18 and the associated diseases (SILs) decreased significantly in women aged 21-26 years in the present, vaccinated group compared to that in similar aged women in 2010-2012 who were unvaccinated. In contrast, the prevalence of HPV and associated diseases may not differ in women aged 27-39 years between the two eras; such subjects may thus serve as a negative control group. Also, HPV prevalence may be higher in present women aged 16-18 years than in women in that age range during the vaccine era, as the former group have not been vaccinated against HPV. The prevalence rates of the other unique high-risk types, namely HPV35, 39, 51, 56, 59, and 68, and probable high-risk types, HPV26, 20, 34, 53, 66, 67, 67, 70, 73, 82, and 85, are unlikely to have been affected by HPV vaccination. However, it is important to monitor the prevalences of these types and the associated SILs, because the types numbered above may become more significant as currently common HPV types are eliminated in the near future.