Safety Evaluation of Seven Years of School-Located Influenza Vaccination—Hawaii, 2007–2013

BACKGROUND:  Hawaii’s Stop Flu at School (SFAS) program has been providing voluntary, free school-located influenza vaccination to students in Kindergarten–8^thgrades since 2007.  More than 90% of eligible schools participate, leading to vaccination of ~60,000 students annually.   Clinic managers at each SFAS clinic are advised to submit incident reports for all unanticipated incidents regardless of severity.  After each season, program managers perform a safety review, and practice changes are subsequently implemented to minimize errors.  Incidents that suggest a true vaccine allergic reaction are reviewed by program physicians to determine an individual’s eligibility for future school-located vaccination.  Although review after each season has shown an overall safe program, no formal safety evaluation of SFAS has been performed.

METHODS:  We reviewed incident reports from all SFAS clinics from 2007–2013; reports were adjudicated and classified as post-vaccination symptoms, potentially preventable (e.g., related to documentation or vaccine administration), or non-preventable incidents (e.g., child kicking vaccinator, child moving during vaccination).  To identify specific areas amenable to correction, we also performed more detailed evaluation of potentially preventable events.

RESULTS:  During 2007–2013, a median of 71,104 (range 62,327–76,729) individuals were vaccinated through SFAS each year.  There were 1–3 (median 3) incident reports submitted per 1,000 persons vaccinated each year.  Vaccine reactions comprised 16–64% (median 54%) of all incident reports per year, preventable events 11–57% (median 21%), and non-preventable incidents 18–37% (median 28%).  Incident reports appeared to increase over time, predominantly because of post-vaccination symptom reports; however, possible allergic vaccine reactions (the reaction of greatest concern) did not show any trend (0–17%, median 6%).  Reviewing preventable events, the most commonly identified incident was improper vaccination technique or procedure (0–21%, median 3%).  Administration of incorrect vaccine type (live-attenuated instead of inactivated influenza vaccine or vice versa) comprised 27% of all reports in the first year of SFAS.  Operational changes to more clearly delineate vaccine formulation to be administered were implemented in successive years, and the error was subsequently noted to be 1%-2%.

CONCLUSIONS:  The SFAS program provides school-located influenza vaccination to tens of thousands of students every season, and yet the rate of incident reports continues to be very low.  Post-season review of reports has allowed us to implement changes to continually increase the safety of the program.  Large, school-located vaccination programs can be performed safely and with few preventable incidents.