RT Journal Article T1 Factors Associated with Adverse Reactions to BNT162b2 COVID-19 Vaccine in a Cohort of 3969 Hospital Workers. A1 Rivera-Izquierdo, Mario A1 Soler-Iborte, Eva A1 de Rojas, Javier Perez A1 Pegalajar-Garcia, Maria Dolores A1 Gil-Villalba, Ana A1 Ruiz-Villaverde, Ricardo A1 Valero-Ubierna, Maria Del Carmen K1 COVID-19 K1 Comirnaty K1 Pfizer K1 adverse events K1 healthcare K1 professionals K1 reactions K1 symptoms K1 vaccination AB Factors associated with adverse reactions to BNT162b2 COVID-19 vaccine reported by hospital workers are unclear. Our aim was to collect all reported adverse events in a cohort of hospital workers and to analyze the factors associated with their presence. We conducted an observational longitudinal study on all hospital workers of our center who received COVID-19 vaccination from 27 December 2020 to 1 September 2021. Information on adverse events was reported telephonically and confirmed through clinical records. Chi-square and t tests as well as multivariate logistic regression models were used. Cluster analysis was designed to explore associations between reactions. A total of 3969 hospital workers were included in the sample. Of the total sample, 182 workers (4.6%) reported adverse events. The most frequent symptoms were general malaise (n = 95), fever (n = 92), arthromyalgia (n = 80), and headache (n = 47). The factors associated with adverse events in adjusted analyses were an antecedent of COVID-19 infection (OR = 2.09, 95% CI: 1.47-2.98), female sex (OR = 1.51, 95% CI: 1.03-2.20), and professional category (OR for physicians = 0.41, 95% CI: 0.21-0.80). We report a low frequency of adverse events in hospital workers after COVID-19 vaccination and no severe reaction. Men and physicians underreported their symptoms. These data should guide future strategies for recording adverse events and future research on COVID-19 vaccination safety. PB MDPI AG SN 2076-393X YR 2021 FD 2021-12-21 LK http://hdl.handle.net/10668/21604 UL http://hdl.handle.net/10668/21604 LA en NO Rivera-Izquierdo M, Soler-Iborte E, de Rojas JP, Pegalajar-GarcĂ­a MD, Gil-Villalba A, Ruiz-Villaverde R, et al . Factors Associated with Adverse Reactions to BNT162b2 COVID-19 Vaccine in a Cohort of 3969 Hospital Workers. Vaccines (Basel). 2021 Dec 23;10(1):15. DS RISalud RD Apr 9, 2025