TABLE 1.

Characteristics of the SARI patients by case and control status, VEBIS hospital network, Europe, 05 October 2023–14 January 2024 (n = 4079).

Characteristic	SARS‐CoV‐2 cases (n = 622)		Test‐negative controls (n = 3457)
	n	%	n	%
Age (years)
18–59	58	9	390	11
60–79	264	42	1610	47
≥ 80	300	48	1457	42
≥ 65	526	85	2802	81
Median (IQR)	79 (71–86)		77 (67–85)
Male	328	53	1758	51
Any chronic condition a	514	83	2888	84
Vaccination status at time of symptom onset
Vaccinated during 2023 autumn campaign b	171	27	1513	44
Not vaccinated during 2023 autumn campaign c	451	73	1944	56
Days since last dose received during 2023 autumn vaccination campaign at time of symptom onset d
14–29 days	18	11	277	18
30–59 days	75	44	680	45
≥ 60 days	78	46	556	37
Median (IQR)	58 (42–71)		52 (35–67)

Abbreviations: SARI: severe acute respiratory infection; VEBIS: Vaccine Effectiveness, Burden and Impact Studies.

^a Common chronic conditions: diabetes, heart disease, lung disease, asthma and immunodeficiency.

^b Vaccinated: received a COVID‐19 vaccine dose after the start of the 2023 autumn vaccination campaign in each study site. Start dates for the 2023 autumn vaccination campaign are shown in Table S1.

^c Not vaccinated: never vaccinated for COVID‐19 or with last COVID‐19 vaccination dose received 180 days prior to the start of the vaccination campaign in each study site. Start dates of the seasonal 2023/24 vaccination campaign are in Table S1.

^d Restricted to those vaccinated during the 2023 autumn vaccination campaign.