tetano
Editor, Senior Moderator
Int J Infect Dis
. 2026 Jan 20:108406.
doi: 10.1016/j.ijid.2026.108406. Online ahead of print.
Serological protection against influenza and cardiovascular events in cardiac ICU patients during seasonal epidemics
Alicia Galar[SUP] 1 [/SUP], Iván Sanz-Muñoz[SUP] 2 [/SUP], José María Eiros[SUP] 2 [/SUP], Roberto Alonso[SUP] 3 [/SUP], Pilar Catalán[SUP] 3 [/SUP], Alejandro Cobos[SUP] 4 [/SUP], Miriam Juárez[SUP] 5 [/SUP], Iago Sousa-Casasnovas[SUP] 5 [/SUP], Maricela Valerio[SUP] 6 [/SUP], Pablo Antunez-Muiños[SUP] 7 [/SUP], Gema Barbeito-Castiñeiras[SUP] 8 [/SUP], Silvia Blanco-Alonso[SUP] 9 [/SUP], María Dolores Folgueira[SUP] 10 [/SUP], José María García-Acuña[SUP] 7 [/SUP], Antonio Lalueza[SUP] 11 [/SUP], Fernando Lázaro[SUP] 12 [/SUP], Esteban Lopez-de-Sa[SUP] 13 [/SUP], Lorena Martín[SUP] 14 [/SUP], Elena Muñez-Rubio[SUP] 9 [/SUP], Francisca Portero[SUP] 15 [/SUP], Antonio Ramos-Martínez[SUP] 9 [/SUP], María Pilar Romero Gómez[SUP] 12 [/SUP], Sandra Rosillo[SUP] 12 [/SUP], Francisco Fernández-Avilés[SUP] 16 [/SUP], Manuel Martínez-Sellés[SUP] 17 [/SUP], Emilio Bouza[SUP] 6 [/SUP], Patricia Munoz[SUP] 6 [/SUP]
Affiliations
Background: Influenza can be associated with acute cardiovascular events, but the impact of serological protection in high-risk patients admitted to Cardiac Intensive Care Units (C-ICUs) is unknown. This study aimed to analyze previous vaccination rate, level of serological protection and laboratory-confirmed influenza, among patients admitted to C-ICUs during influenza season, and its association with cardiovascular events.
Methods: Prospective multicenter study of all patients admitted to C-ICUs during 2017-2018, 2018-2019, and 2019-2020 influenza seasons. A systematic search for influenza was performed using the Xpert Xpress Flu/RSV assay (Cepheid, Sunnyvale, CA, USA). The seroprotection rate was assessed by analyzing the percentage of patients with antibody titers against influenza ≥1/40, and the intensity of seroprotection by evaluating the geometric mean titers of these antibodies.
Results: From 397 patients, 245 (61.7%) reported previous influenza vaccine. A total of 23 patients had laboratory-confirmed influenza (23/397, 5.8%). Overall, the seroprotection rate was significantly higher for influenza A than for B (84.6%, vs. 37.5%, p<0.001) and higher in vaccinated than in non-vaccinated group. The highest seroprotection rate and intensity was observed for subtype A(H3N2), followed by A(H1N1)pdm09, B/Victoria, and finally B/Yamagata. Compared unvaccinated patients, those with prior vaccination had lower rates of ST-segment elevation myocardial infarction (28.2% vs. 40.8%, p=0.009), pulmonary embolism (0.8% vs. 4.6%, p=0.014), and severe clinical presentation (53.1% vs. 67.1%, p=0.006).
Conclusions: Serological protection was higher against influenza A than B, especially for the A (H3N2) subtype. ST-segment elevation myocardial infarction, pulmonary embolism, and severe clinical presentation appear to be reduced with influenza vaccination.
Keywords: Cardiac Intensive Care Unit; Cardiovascular events; Influenza Vaccines; Laboratory-confirmed influenza; Myocardial Infarction; Seroprotection.
. 2026 Jan 20:108406.
doi: 10.1016/j.ijid.2026.108406. Online ahead of print.
Serological protection against influenza and cardiovascular events in cardiac ICU patients during seasonal epidemics
Alicia Galar[SUP] 1 [/SUP], Iván Sanz-Muñoz[SUP] 2 [/SUP], José María Eiros[SUP] 2 [/SUP], Roberto Alonso[SUP] 3 [/SUP], Pilar Catalán[SUP] 3 [/SUP], Alejandro Cobos[SUP] 4 [/SUP], Miriam Juárez[SUP] 5 [/SUP], Iago Sousa-Casasnovas[SUP] 5 [/SUP], Maricela Valerio[SUP] 6 [/SUP], Pablo Antunez-Muiños[SUP] 7 [/SUP], Gema Barbeito-Castiñeiras[SUP] 8 [/SUP], Silvia Blanco-Alonso[SUP] 9 [/SUP], María Dolores Folgueira[SUP] 10 [/SUP], José María García-Acuña[SUP] 7 [/SUP], Antonio Lalueza[SUP] 11 [/SUP], Fernando Lázaro[SUP] 12 [/SUP], Esteban Lopez-de-Sa[SUP] 13 [/SUP], Lorena Martín[SUP] 14 [/SUP], Elena Muñez-Rubio[SUP] 9 [/SUP], Francisca Portero[SUP] 15 [/SUP], Antonio Ramos-Martínez[SUP] 9 [/SUP], María Pilar Romero Gómez[SUP] 12 [/SUP], Sandra Rosillo[SUP] 12 [/SUP], Francisco Fernández-Avilés[SUP] 16 [/SUP], Manuel Martínez-Sellés[SUP] 17 [/SUP], Emilio Bouza[SUP] 6 [/SUP], Patricia Munoz[SUP] 6 [/SUP]
Affiliations
- PMID: 41570890
- DOI: 10.1016/j.ijid.2026.108406
Background: Influenza can be associated with acute cardiovascular events, but the impact of serological protection in high-risk patients admitted to Cardiac Intensive Care Units (C-ICUs) is unknown. This study aimed to analyze previous vaccination rate, level of serological protection and laboratory-confirmed influenza, among patients admitted to C-ICUs during influenza season, and its association with cardiovascular events.
Methods: Prospective multicenter study of all patients admitted to C-ICUs during 2017-2018, 2018-2019, and 2019-2020 influenza seasons. A systematic search for influenza was performed using the Xpert Xpress Flu/RSV assay (Cepheid, Sunnyvale, CA, USA). The seroprotection rate was assessed by analyzing the percentage of patients with antibody titers against influenza ≥1/40, and the intensity of seroprotection by evaluating the geometric mean titers of these antibodies.
Results: From 397 patients, 245 (61.7%) reported previous influenza vaccine. A total of 23 patients had laboratory-confirmed influenza (23/397, 5.8%). Overall, the seroprotection rate was significantly higher for influenza A than for B (84.6%, vs. 37.5%, p<0.001) and higher in vaccinated than in non-vaccinated group. The highest seroprotection rate and intensity was observed for subtype A(H3N2), followed by A(H1N1)pdm09, B/Victoria, and finally B/Yamagata. Compared unvaccinated patients, those with prior vaccination had lower rates of ST-segment elevation myocardial infarction (28.2% vs. 40.8%, p=0.009), pulmonary embolism (0.8% vs. 4.6%, p=0.014), and severe clinical presentation (53.1% vs. 67.1%, p=0.006).
Conclusions: Serological protection was higher against influenza A than B, especially for the A (H3N2) subtype. ST-segment elevation myocardial infarction, pulmonary embolism, and severe clinical presentation appear to be reduced with influenza vaccination.
Keywords: Cardiac Intensive Care Unit; Cardiovascular events; Influenza Vaccines; Laboratory-confirmed influenza; Myocardial Infarction; Seroprotection.