NIPH Clinical Trials Search

A Questionnaire-Based Study on the Actual Timing of Initiation of Japanese Encephalitis Vaccination

Basic Information

Recruitment status	Recruiting
Health condition(s) or Problem(s) studied	Japanese Encephalitis
Date of first enrollment	04/12/2025
Target sample size	2700
Countries of recruitment
Study type	Observational
Intervention(s)

Outcome(s)

Primary Outcome

Proportion of individuals who initiated the first dose of Japanese encephalitis vaccine before age 3, nationwide and by regional block

Secondary Outcome

Proportion of individuals who started vaccination before the age of 3 within each block (by prefecture) Annual trend in the proportion of individuals who started vaccination before the age of 3 (nationwide and by block) Proportion of reasons for not receiving vaccination among unvaccinated individuals Proportion of individuals who started vaccination before the age of 3 according to sources of information influencing vaccination decision (doctor's guidance, municipal notifications, SNS, vaccination schedule apps) (nationwide and by block) For cases where the source of information influencing vaccination decision was doctor's guidance: proportion of individuals who started vaccination before the age of 3 according to opportunities for guidance from medical institutions (during health checkups, after other vaccinations, during illness visits) (nationwide and by block) For cases where the source of information influencing vaccination decision was municipal notifications: proportion of individuals who started vaccination before the age of 3 according to timing of notifications from municipalities (during age 0, age 1, age 2, or after age 3) (nationwide and by block)

Key inclusion & exclusion criteria

Age minimum	>= 4age old
Age maximum	< 7age old
Gender	Both
Include criteria	1.Parents registered as panel members of Macromill Inc. who have children aged 4 to 6 years 2.Individuals who agreed, at the time of the survey, to allow anonymized survey results to be published in academic literature 3.Individuals who can confirm the month of the first dose of the Japanese encephalitis vaccine for their 4 to 6 year-old child using the Maternal and Child Health Handbook
Exclude criteria	none