Monitoring the safety of high-dose, trivalent inactivated influenza vaccine in the vaccine adverse event reporting system (VAERS), 2011 – 2019

Abstract Background On 12/23/2009 a new high-dose trivalent inactivated influenza vaccine (IIV3-HD) was licensed for adults aged ≥65 years. We assessed the post-licensure safety data for IIV3-HD in the Vaccine Adverse Event Reporting System (VAERS) during 2011–2019. Methods We searched VAERS for reports after IIV3-HD during 1/1/2011–06/30/2019 in persons aged ≥65 years. Medical records were reviewed for all death reports and for certain pre-specified conditions (e.g. Guillain Barre Syndrome [GBS], anaphylaxis). We also reviewed certain groups who received IIV3-HD erroneously (e.g. pregnant women, children). Empirical Bayesian data mining was used to identify disproportional reporting. Results VAERS received 12,320 reports after IIV3-HD;723 reports (5.9%) were serious. The most common adverse events (AEs) among serious reports were pyrexia (30.2%), asthenia (28.9%), and dyspnea (24.9%), and among non-serious reports were injection site erythema (16.8%), pain in extremity (15.8%), and injection site pain (14.2%). Among 55 death reports, the most common causes of death were diseases of the circulatory system (n = 23;41.8%). Based on medical record review, there were 61 reports of GBS and 13 of anaphylaxis. There were 13 reports of pregnant-women who inadvertently received IIV3-HD; three reports described arm pain or local reactions, and 10 did not report any AE. Among 59 reports of children who erroneously received IIV3-HD, 31 experienced an AE (most commonly injection site or constitutional reactions) and the remaining 28 reports did not describe any AE. Conclusions Post-licensure safety data of IIV3-HD during 9 influenza seasons revealed no new or unexpected safety concerns among individuals ≥65 years. Inadvertent administration of IIV3-HD to children or pregnant women was observed, although with no serious AEs reported. Training and education of providers in vaccine recommendations and groups for whom the vaccine is indicated may help in preventing these vaccine administration errors. This review provides baseline information for future monitoring of the quadrivalent-high-dose influenza vaccine.