Evaluation of a school entry immunization record check strategy in 4 counties of Ningxia and Hubei provinces, China

SECS provides opportunities to identify incompletely vaccinated children, improve coverage, and remind families of school-age children about up-coming vaccinations; SECS has potential to improve completeness of IIS data and enrollment of children in immunization clinics. Evidence-based policy with implementation guidance and routine monitoring are necessary to improve China's school entry checking strategy.