Journal of Infection and Chemotherapy

Stopping the HPV vaccine crisis in Japan: Quantifying the benefits and risks of HPV vaccination in quality-adjusted life-years for appropriate decision-making

The human papilloma virus (HPV) vaccination coverage rate in Japan has dropped dramatically from more than 70% to less than 1% since 2013. With conflicting information and a lack of quantification of the benefits and risks of the HPV vaccine, parents have been hindered in making their decision. We quantified the benefits and risks of the HPV vaccine in terms of quality-adjusted life-years (QALYs), to help their informed decision. A literature search was performed to determine the incidence and burden of each outcome in a decision tree model. The benefits and the risks of the HPV vaccination were determined in QALY change with a sensitivity analysis. The benefits of the HPV vaccine in terms of QALYs gained were 703.72, 14.45, and 30.83/100,000 persons for cervical cancer, cervical intraepithelial neoplasm 3 (CIN 3), and genital warts, respectively. The QALY loss due to acute adverse reactions, chronic adverse reactions without assistance needs, and chronic adverse reactions with assistance needs were 0.07, 5.83, and 5.82/100,000 persons, respectively. The risk/benefit ratio in QALY change in the base case was 0.0156. In all scenarios, the benefit of the HPV vaccine was significantly greater than the risk. The benefits are much greater than the risks, even if it is assumed that all reported adverse events were due to the vaccination. The Japanese government and health care providers should immediately recommend the HPV vaccine to all adolescent girls irrespective of any causal links between the vaccine and reported adverse events.

Human Papillomavirus vaccination awareness and uptake among healthcare students in Japan

The vaccination rate for HPV (Human Papillomavirus) has remained significantly low in Japan because of the administrative suspension of active recommendation. This study investigates the awareness and uptake of the HPV vaccine among healthcare students in Japan following the reinstatement of active recommendation for young women in April 2022. A web-based survey was administered to 2567 healthcare students from Okayama and Shujitsu Universities in Japan in July 2023. The survey assessed participants' backgrounds, immunization status, awareness of vaccine recommendations, and knowledge of cervical cancer across various demographics, including sex, academic year, and department (Medicine, Health Science, Pharmaceutical, and Dentistry). The response rate was 36.3 % (933 students; 181 male, 739 female, and 13 unspecified gender). The overall immunization rate among female students was 55.6 %, with higher rates observed in medical (73.8 %) and dental (63.0 %) students. Awareness of the government's change in vaccine recommendation was notably high among female and senior male students. Over half of the female students (54.7 %) reported receiving vaccinations based on their parents' advice. Among those unvaccinated but interested in future immunization, concerns about adverse reactions (47.4 %) and challenges in scheduling vaccinations (29.1 %) were predominant. Healthcare students exhibited a higher HPV vaccination rate than the general population. Ongoing education to improve vaccine literacy is crucial for augmenting HPV vaccination rates in Japan.

Knowledge and awareness of human papillomavirus (HPV) influence HPV vaccination uptake among the catch-up generation in Japan

Despite its importance for young women, the human papillomavirus (HPV) vaccination coverage remains low in Japan. Previous studies have examined behaviors related to HPV catch-up vaccination. Uniquely, this study aimed to investigate perceptions and factors influencing vaccination coverage among female university students in the catch-up program, focusing on both medical and non-medical undergraduates. A web-based survey was conducted at Kochi University from January 16 to February 13, 2023, targeting female students born between April 2, 1997, and April 1, 2006. The survey collected demographic data and assessed knowledge of HPV infection, cervical cancer, and preventive measures. Chi-square tests and logistic regression analyses were used to identify differences between vaccinated and unvaccinated groups as well as factors related to HPV vaccination. Of the 310 participants, 39.0 % were vaccinated against HPV, 35.2 % were freshmen, and 75.2 % were in medical science programs. HPV vaccination was significantly associated with being in upper years of university (OR = 3.78-42.83), studying medical sciences (OR = 1.93), undergoing cervical cancer screening (OR = 4.04), and receiving free vaccination vouchers (OR = 2.03). Knowledge and awareness of HPV and cervical cancer significantly contribute to higher vaccination uptake in the generation receiving catch-up vaccinations. Tailoring information and distributing free vaccination vouchers could enhance HPV vaccination rates and awareness in this group.

Adult-onset botulism in a Japanese woman with prolonged spore excretion

We report a case of an 80-year-old woman with botulism from 2020 in Osaka, Japan. The patient complained of dysarthria and dizziness. On the same day, the patient developed respiratory failure, and was intubated and placed on mechanical ventilation. Subsequently, ophthalmoparesis and quadriparesis progressed rapidly. Ten days after onset, the patient failed to respond to any external stimulation. Blood tests showed anemia, and computed tomography revealed undiagnosed cervical cancer. Initially, diagnosis of neuromuscular junction disorder and acute motor neuropathy, including paraneoplastic syndrome, were considered. However, intravenous immunoglobulin therapy and plasma exchange were ineffective. A fecal sample on day 30 showed a large number of C. botulinum spores. On day 34, a mouse bioassay revealed botulinum toxin type A in the patient's serum; therefore, a botulinum antitoxin was administered. Later, the patient's muscle strength was gradually improved. However, severe muscle paralysis persisted, and the patient died of cachexia owing to cervical cancer on day 196. The etiology of this case was unknown because no contaminated food was identified during an inspection of the patient's home. Fecal 16S rRNA gene sequencing revealed dysbiosis of the intestinal microbiota with abundant Enterococcus species. Long-lasting excretion of substantial botulinum spores even on day 30 indicated colonization of C. botulinum in the intestinal tract. This case suggests that C. botulinum colonization with co-existing intestinal dysbiosis may be associated with severe and prolonged symptoms of botulism.