Table. Incidence of very severe lower respiratory tract infection in the Lyon cohorta by season, university hospital of Lyon, France, epidemiological seasons 2019/20−2020/21.
| Incidence and relative risk reduction by age group | Season 2019/20 | Season 2020/21 |
|---|---|---|
| Births from 1 January to 31 December 2020 | Births from 1 April 2020 to April 2021 | |
| Incidence of laboratory-confirmed RSV hospitalisation for VS-LRTI < 1 year of age | 13.6/1,000 (95% CI: 11.0−16.0) | 8.8/1,000 (95% CI: 6.0−10.0) |
| RR reduction of the incidence of hospitalisation for VS-LRTI < 1 year of age | 1.5-fold lower (95% CI: 1.2−2.1) | |
| Incidence of laboratory-confirmed RSV hospitalisation for VS-LRTI ≤3 months of age | 10.4/1,000 (95% CI: 8.0−13.0) | 5.2/1,000 (95% CI 4.0−7.0) |
| RR reduction of the incidence of hospitalisation for VS-LRTI ≤3 months of age | 2.0-fold lower (95% CI: 1.4−2.9) | |
| Total number of VS-LRTI case in HCL cohort aged over 3 months up to 1 year | 29 | 32 |
CI: confidence interval; HCL: Hospices Civils de Lyon; RSV: respiratory syncytial virus; RR: relative risk; VS-LRTI: very severe lower respiratory tract infection.
a Children born at the Hospices Civils de Lyon over three consecutive years (1 June 2018–01 April 2021) whose parents are living in the Métropole de Lyon.
To take into account the observed 3-month delay in the 2020/21 RSV epidemic, for this season, only births from 1 April 2020 to 1 April 2021 were considered.