Spontaneously reported adverse events following COVID-19 basic and booster immunizations in the Netherlands.

INTRODUCTION: The rapid roll-out of novel COVID-19 vaccines made near real-time post-marketing safety surveillance essential to identify rare and long-term adverse events following immunization (AEFIs). In light of the ongoing booster vaccination campaigns, it is key to monitor changes in observed safety patterns post-vaccination. The effect of sequential COVID-19 vaccinations, as well as heterologous vaccination sequences, on the observed post-vaccination safety pattern, remains largely unknown. METHODS: The primary objective of this study was to describe the profile of spontaneously reported AEFIs following COVID-19 vaccination in the Netherlands, including the primary and booster series. Reports from consumers and healthcare professionals were collected via a COVID-19 vaccine-tailored online reporting form by the National Pharmacovigilance Centre Lareb (Lareb) between 6 January 2021 and 31 August 2022. The data were used to describe the most frequently reported AEFIs per vaccination moment, the consumer experienced burden per AEFI, and differences in AEFIs reported for homologous and heterologous vaccination sequences. RESULTS: Lareb received 227,884 spontaneous reports over a period of twenty months. Overall, a high degree of similarity in local and systemic AEFIs per vaccination moment was observed, with no apparent change in the number of reports of serious adverse events after multiple COVID-19 vaccinations. No differences in the pattern of reported AEFIs per vaccination sequence was observed. CONCLUSION: Spontaneous reported AEFIs demonstrated a similar reporting pattern for homologous and heterologous primary and booster series of COVID-19 vaccination in the Netherlands.

COVID-19 vaccine reactogenicity - A cohort event monitoring study in the Netherlands using patient reported outcomes.

OBJECTIVES: To explore factors that are associated with reactogenicity in general and systemic after the first dose of COVID-19 vaccine in the Netherlands. DESIGN: A web-based prospective cohort design using patient reported outcomes (PROs). SETTING: Any person who has been vaccinated with any brand of COVID-19 vaccine in the Dutch COVID immunization programme. PARTICIPANTS: 22,184 participants. Of these, 13,959 (62.9%) experienced reactogenicity in general and 11,979 (54.0%) systemic reactogenicity within 7 days after vaccination. MAIN OUTCOME MEASURES: Factors that are associated with the occurrence of reactogenicity after COVID-19 vaccination. RESULTS: Compared to the Comirnaty® vaccine, the highest odds ratio (OR) for developing reactogenicity was for the Vaxzevria® vaccine (OR 5.18) followed by Spikevax® (OR 2.16), and Janssen (OR 1.65). Participants with a history of COVID-19 disease had a 3.10 increased odds for reactogenicity. Women had a 2.08 increased odds compared to men. Older participants experienced less reactogenicity. Compared to the age group < 50, the ORs for the age groups 50-60, 61-79, and ≥80 were 0.36, 0.15, and 0.10 respectively. The use of an antipyretic drug, or a drug for nervous system disorders gave an increased odds of 1.34 and 1.16 respectively. A body mass index of 25.0-29.9 and over 30 was negatively associated with reactogenicity (OR 0.87 and OR 0.72 respectively). Comorbidities that were associated with reactogenicity were cardiac disorders (OR 1.26), respiratory disorders (OR 1.31), psychiatric disorders (1.37), reproductive disorders (OR 1.54), and eye disorders (OR 1.55). The factors associated with systemic reactogenicity were mostly comparable, but there were differences for comorbidities, drug use, and the strength of the regression coefficient. CONCLUSIONS: This extensive study with over 22,000 vaccine recipients in the Netherlands demonstrated that, taken into account all factors in the model, the Comirnaty® vaccine gave the least and the Vaxzevria® vaccine the most reactogenicity in general and systemic after the first dose. Also a person with a history of COVID-19 disease, female sex and younger age had an increased odds for experiencing reactogenicity after vaccination.