A review of factors affecting vaccine preventable disease in Japan.

Japan is well known as a country with a strong health record. However its incidence rates of vaccine preventable diseases (VPD) such as hepatitis B, measles, mumps, rubella, and varicella remain higher than other developed countries. This article reviews the factors that contribute to the high rates of VPD in Japan. These include historical and political factors that delayed the introduction of several important vaccines until recently. Access has also been affected by vaccines being divided into government-funded "routine" (eg, polio, pertussis) and self-pay "voluntary" groups (eg, hepatitis A and B). Routine vaccines have higher rates of administration than voluntary vaccines. Administration factors include differences in well child care schedules, the approach to simultaneous vaccination, vaccination contraindication due to fever, and vaccination spacing. Parental factors include low intention to fully vaccinate their children and misperceptions about side effects and efficacy. There are also provider knowledge gaps regarding indications, adverse effects, interval, and simultaneous vaccination. These multifactorial issues combine to produce lower population immunization rates and a higher incidence of VPD than other developed countries. This article will provide insight into the current situation of Japanese vaccinations, the issues to be addressed and suggestions for public health promotion.