IntroductionNuvaxovid became available in Australia from February 2022, a year after the first COVID-19 vaccines. This protein-based vaccine was an alternative for people who had had an adverse event to and/or were hesitant to receive an mRNA or adenovirus-based COVID-19 vaccine. Although safety from clinical trials was reassuring, small trial populations, low administration rates and limited post-licensure intelligence meant potential rare adverse events were underinformed.AimWe aimed to describe Nuvaxovid's safety profile in a real-world setting.MethodsWe conducted a retrospective observational analysis of adverse events following immunisation (AEFI) spontaneously reported to SAFEVAC, the integrated vaccine safety surveillance system in Victoria and Western Australia. Reports from 14 February 2022 to 30 June 2023 were analysed by vaccinee demographics, reported reactions and COVID-19 vaccine dose, and compared as reporting rates (RR) per 100,000 doses administered.ResultsWe received 356 AEFI reports, following 102,946 Nuvaxovid doses administered. Rates were higher after dose 1 than dose 2 (rate ratio: 1.5, p = 0.0008), primary series than booster (rate ratio: 2.4, p < 0.0001), and in females vs males (rate ratio: 1.4, p = 0.004). Clinically confirmed serious AEFI included 94 cases of chest pain (RR = 91.3), two myocarditis (RR = 1.9) and 20 pericarditis (RR = 19.4). Guillain-Barré syndrome or thrombosis with thrombocytopaenia syndromes were not reported, nor deaths attributable to vaccination.ConclusionSAFEVAC's collaborative data model enabled pooling of clinically reviewed data across jurisdictions, increasing the safety profile evidence for Nuvaxovid and improving the odds for identification and description of rare events. This analysis affirmed the safety profile of Nuvaxovid.
Keywords: Vaccine safety; adverse events; immunisation, COVID, Nuvaxovid, myocarditis, pericarditis; surveillance.