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

BACKGROUND

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.

METHOD

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.

RESULT

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.

CONCLUSION

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.