Changes and remaining challenges for the Japanese immunization program: Closing the vaccine gap.

Area of Science:

• Pediatrics
• Immunology
• Public Health

Background:

• Japan's immunization program has advanced significantly since 2009 with new vaccines integrated into the National Immunization Program (NIP).
• A 2020 revision to Japan's immunization law added rotavirus vaccines to the NIP and removed concerns regarding vaccine intervals.
• The Japan Pediatric Society released a Japanese Vaccine Information Statement (VIS) in 2018 for caregiver education.

Purpose of the Study:

• To review the progress and identify ongoing challenges in Japan's national immunization program.
• To highlight achievements such as the inclusion of rotavirus vaccines and revised vaccine interval rules.
• To address future needs including booster doses, HPV vaccine recommendations, and the addition of mumps and influenza vaccines.

Main Methods:

• Review of policy changes and program updates in Japanese immunization.
• Analysis of vaccine effectiveness and intussusception incidence studies.
• Assessment of current vaccination trends, particularly during the COVID-19 pandemic.

Main Results:

• Rotavirus vaccines were added to the NIP in 2020, 10 years post-introduction.
• Vaccine interval rules were revised, addressing a long-standing concern.
• While infant vaccination rates remained stable, rates declined in toddlers and school-aged children during the COVID-19 pandemic.

Conclusions:

• Japan's immunization program has seen progress, but challenges remain in vaccine uptake and program expansion.
• Specific areas for improvement include pertussis boosters, HPV vaccine recommendations, and adding mumps and influenza vaccines to the NIP.
• Urgent action is required to address declining vaccination rates in older children and ensure protection against vaccine-preventable diseases.