Insulin Mistaken for Influenza Vaccine in School Clinic
As organizations prepare for influenza season, it is important to recognize how changes in vaccine presentation can introduce new medication safety risks. ISMP was informed of an event in which a school nurse intended to administer a 0.5 mL dose of FLUZONE (influenza vaccine) to a student but instead administered 50 units (0.5 mL) of LYUMJEV (insulin lispro-aabc) intramuscularly (Figure 1). The insulin belonged to another student and had been stored in the same refrigerator as the vaccine supply. The nurse prepared the dose in a lighted storage closet because the health office was intentionally kept dark while another student rested in the room.
Figure 1. Sanofi’s Fluzone vaccine for 6 months of age and older (left) was intended, but Lilly’s Lyumjev (right) was administered.
After administration, the nurse recognized that insulin lispro, rather than influenza vaccine, had been selected. The nurse notified the patient of the error, and they were transported to a local ED, where intravenous dextrose was administered and blood glucose levels were monitored. The patient was discharged later that day after glucose values stabilized.
Several factors may have contributed to the error. The nurse was working in a constrained preparation area and managing multiple responsibilities at the time of dose preparation. Barcode scanning was not available, and standard verification practices were not completed before administration. The presence of student-owned insulin in the same refrigerator as vaccine stock increased the opportunity for selection errors. In addition, the clinic’s usual influenza vaccination process had changed because multi-dose vaccine vials, obtained due to supply shortages, were being used instead of prefilled syringes, creating an unfamiliar workflow.
This is not the first time that errors have been reported where vials of insulin have been mistaken as influenza vaccines. Our November 19, 2020 article, Learning from Influenza Vaccine Errors to Prepare for COVID-19 Vaccination Campaigns, described cases of harmful vaccine errors that happened due to comingled, unsegregated refrigerator storage of vaccines and medications.
As immunization clinics prepare for influenza season, they should review vaccine storage and administration workflows. Store vaccines separately from patient/student-specific medications, particularly high-alert medications such as insulin, using clearly labeled bins or designated compartments. Reassess processes whenever vaccine products, packaging, or storage locations change, including transitions from prefilled syringes to multi-dose vials. Prepare and verify doses in a well-lit area with minimal distractions and utilize barcode scanning prior to administration whenever possible. If barcode scanning is not possible, perform a final check of the patient, drug, dose, route, and purpose prior to administration. Regularly review clinic inventory for look-alike or high-alert medications and educate staff about vaccine-related medication risks before influenza vaccination activities begin. Whenever possible, use commercially available single-dose prefilled syringes for vaccines.