[SHIFT IN THE BCG VACCINATION AGE REGARDING THE 2013 REVISION OF THE JAPANESE VACCINATION SCHEDULE].

Abstract

Objectives: In Japan; infants ranging from 3 to 4 months of age were excluded from the stan- dard vaccination period for Bacillus Calmette-Gu6rin in 2013. The aim of this study was to evaluate the contri- bution of immunization methods and the means of communication employed by municipalities to inform the parents of infants about this revision on the shift in the immunization age.

Methods: In 35 municipalities, I assessed the monthly proportion of infants vaccinated between 3 and 4 months of age relative to all infants in 2013, in reference to the immunization method (group or individual immunization) and the application of two-way communication (TWC) between the municipalities and parents, The types of communication that were defined as TWC were as follows: home guidance and face-to-face explanation at the health examination for the infants.

Results: In most municipalities, the proportion of infants vaccinated between 3 and 4 months of age relative to all infants gradually decreased after following revision of the vaccination period. No signi- ficant differences were observed in these proportions between the municipalities with group immunization and those with individual immunization; however, the variability of these proportions among the municipal- ities with group immunization increased with duration. In the municipalities with individual immunization schedules, the application of TWC to parents promoted the decrease of infants vaccinated between 3 and 4 months of age, as compared to that seen in the other municipalities.

Conclusions: The municipalities with group immunization were characterized by variation in the shift of the immunization age. TWC with parents accelerated this shift in the municipalities with individual immunization.