Resumen de Significant sise in SARS-CoV-2 reinfection rate in vaccinated hospital workers during the omicron wave: A prospective cohort study
Eric Ochoa Hein, Patricia E. Leal Morán, Karen A Nava Guzmán, Abril T. Vargas Fernández, José F. Vargas Fernández, Fabricio Díaz Rodríguez, Joel Armando Rayas Bernal, Ricardo González González, Pavel Vázquez González, Martha A. Huertas Jiménez, Sandra Rajme López, María del Pilar Ramos Cervantes, Violeta Ibarra González, Luís García Andrade, Fernando Ledesma Barrientos, Alfredo Ponce de León, José Sifuentes Osornio, Arturo Galindo Fraga
Background: Relatively low SARS-CoV-2 reinfection rates have been reported in vaccinated individuals, but updates considering the Omicron variant are lacking. Objective: The objective of the study was to provide a current estimate of the SARS-CoV-2 reinfection rate in a highly immunized population. Methods: A prospective cohort of Mexican hospital workers was followed (March 2020-February 2022). Reinfection was defined as the occurrence of two or more episodes of COVID-19 separated by a period of ≥ 90 days without symptoms. The reinfection rate was calculated as the number of reinfection episodes per 100,000 persons per day. Results: A total of 3732 medical consultations were provided to 2700 workers, of whom 1388 (51.4%) were confirmed COVID-19 cases. A total of 73 reinfection cases were identified, of whom 71 (97.3%) had completed their primary vaccination series and 22 (30.1%) had had a booster dose before the second episode. The overall reinfection rate was 23.1 per 100,000 persons per day (as compared to a rate of 1.9 per 100,000 persons per day before the Omicron wave). Conclusions: The SARS-CoV-2 reinfection rate rose significantly during the Omicron wave despite a high primary vaccination coverage rate. Almost one-third of reinfected workers had a vaccine booster ≥ 14 days before the last COVID-19 episode.
