Abstract: In 2015, Chile changed the target population for the national influenza immunization campaign and added children under six years old. Using national school attendance data, I test whether childhood flu vaccination has a positive short-term effect on educational outcomes. The intention-to-treat estimates suggest that the influenza vaccine positively impacts school attendance, which is especially visible during the flu season and for children from lower-income families. Moreover, I study whether age-eligible children attend more or less to school on the vaccination date since educational establishments serve as vaccination sites. I find no consistent evidence of manipulation on demand for immunization.