tetano
Editor, Senior Moderator
Infect Dis Ther
. 2026 Mar 27.
doi: 10.1007/s40121-026-01332-5. Online ahead of print.
Post-COVID-19 Burden of Severe Influenza in England Among Overall Population and High-Risk Groups: Results From the INFORM Study, 2022-2023
Wilhelmine Meeraus[SUP] 1 [/SUP], Lucy Carty[SUP] 2 [/SUP], Sabada Dube[SUP] 3 [/SUP], Kathryn Evans[SUP] 4 [/SUP], Rachael A Evans[SUP] 5 [/SUP], Ana Goios[SUP] 6 [/SUP], Nahila Justo[SUP] 7 [/SUP], Yi Lu[SUP] 8 [/SUP], Jennifer K Quint[SUP] 9 [/SUP], Sylvia Taylor[SUP] 3 [/SUP], Sudhir Venkatesan[SUP] 2 [/SUP], Lance Turtle[SUP] 10 [/SUP]
Affiliations
Introduction: We describe the burden of severe influenza in England overall, and in risk groups (as defined by age, immunocompromise, and other comorbidities) and those with recent COVID-19.
Methods: The INFORM (INvestigation oF cOvid-19 Risk among iMmunocompromised populations) cohort uses pseudonymised, routinely collected electronic health records of individuals aged ≥ 12 years from a random 25% sample of England's population (N = 12.1 million). In this analysis, during 1 July 2022 to 30 June 2023, crude incidence rates (IRs) and age- and sex-adjusted IR ratios were estimated for severe influenza outcomes of hospitalisation, intensive care unit (ICU) admission and death. The analyses were repeated for outcomes of severe influenza with recent COVID-19 (< 6 months).
Results: The analysis sample comprised 12,075,920 individuals aged ≥ 12 years; 3.9% were immunocompromised. Overall, IRs of severe influenza were 10.51 (hospitalisations), 0.35 (ICU admissions) and 0.73 (deaths) per 10,000 person-years. Of those with influenza hospitalisation, 13.1% had recent COVID-19. Overall, influenza hospitalisation IRs per 10,000 person-years increased with advancing age, from 3.56 for adolescents aged 12-17 years to 58.43 for adults aged ≥ 80 years. Compared with other age groups, among hospitalised individuals, the highest intensity of management occurred in adolescents aged 12-17 years, based on the proportion of influenza hospitalisations that involved ICU admission (6.2%) or mechanical ventilation (3.0%) in this age group. Increased age- and sex-adjusted risk of severe influenza outcomes was observed among individuals with immunocompromise and other comorbidities.
Conclusions: Seasonal severe influenza was observed in the general population aged ≥ 12 years in England in 2022-2023, with a disproportionately higher burden recorded in risk groups (as defined by age, immunocompromise, recent COVID-19 and other comorbidities). These data reinforce continued efforts to immunise individuals against seasonal influenza.
Trial registration: International Standard Randomised Controlled Trial Number Registry: ISRCTN53375662.
Keywords: Age; Comorbidity; High risk; Immunocompromised; Influenza.
. 2026 Mar 27.
doi: 10.1007/s40121-026-01332-5. Online ahead of print.
Post-COVID-19 Burden of Severe Influenza in England Among Overall Population and High-Risk Groups: Results From the INFORM Study, 2022-2023
Wilhelmine Meeraus[SUP] 1 [/SUP], Lucy Carty[SUP] 2 [/SUP], Sabada Dube[SUP] 3 [/SUP], Kathryn Evans[SUP] 4 [/SUP], Rachael A Evans[SUP] 5 [/SUP], Ana Goios[SUP] 6 [/SUP], Nahila Justo[SUP] 7 [/SUP], Yi Lu[SUP] 8 [/SUP], Jennifer K Quint[SUP] 9 [/SUP], Sylvia Taylor[SUP] 3 [/SUP], Sudhir Venkatesan[SUP] 2 [/SUP], Lance Turtle[SUP] 10 [/SUP]
Affiliations
- PMID: 41896400
- DOI: 10.1007/s40121-026-01332-5
Introduction: We describe the burden of severe influenza in England overall, and in risk groups (as defined by age, immunocompromise, and other comorbidities) and those with recent COVID-19.
Methods: The INFORM (INvestigation oF cOvid-19 Risk among iMmunocompromised populations) cohort uses pseudonymised, routinely collected electronic health records of individuals aged ≥ 12 years from a random 25% sample of England's population (N = 12.1 million). In this analysis, during 1 July 2022 to 30 June 2023, crude incidence rates (IRs) and age- and sex-adjusted IR ratios were estimated for severe influenza outcomes of hospitalisation, intensive care unit (ICU) admission and death. The analyses were repeated for outcomes of severe influenza with recent COVID-19 (< 6 months).
Results: The analysis sample comprised 12,075,920 individuals aged ≥ 12 years; 3.9% were immunocompromised. Overall, IRs of severe influenza were 10.51 (hospitalisations), 0.35 (ICU admissions) and 0.73 (deaths) per 10,000 person-years. Of those with influenza hospitalisation, 13.1% had recent COVID-19. Overall, influenza hospitalisation IRs per 10,000 person-years increased with advancing age, from 3.56 for adolescents aged 12-17 years to 58.43 for adults aged ≥ 80 years. Compared with other age groups, among hospitalised individuals, the highest intensity of management occurred in adolescents aged 12-17 years, based on the proportion of influenza hospitalisations that involved ICU admission (6.2%) or mechanical ventilation (3.0%) in this age group. Increased age- and sex-adjusted risk of severe influenza outcomes was observed among individuals with immunocompromise and other comorbidities.
Conclusions: Seasonal severe influenza was observed in the general population aged ≥ 12 years in England in 2022-2023, with a disproportionately higher burden recorded in risk groups (as defined by age, immunocompromise, recent COVID-19 and other comorbidities). These data reinforce continued efforts to immunise individuals against seasonal influenza.
Trial registration: International Standard Randomised Controlled Trial Number Registry: ISRCTN53375662.
Keywords: Age; Comorbidity; High risk; Immunocompromised; Influenza.