Table 1 Demographic, health-related and laboratory characteristics of the study population, %

Age groups

 65–70 y

35

35

35

 71–75 y

37

35

37

 76–80 y

28

29

28

Body Mass Index^a

 Underweight (≤18.49 kg/m²)

1.0

2.4

0

 Normal weight (18.50–24.99 kg/m²)

36

46

28

 Overweight (25.00–29.99 kg/m²)

45

32

55

 Obesity (≥30.00 kg/m²)

18

20

17

Hypertension^b

 Yes

56

54

57

 No

44

46

43

Heart attack^c

 Yes

6.0

4.7

7.0

 No

93

94

92

 Don’t know

0.50

0

0.87

 Missing values

0.50

1.2

0

Cancer^c

 Yes

20

18

22

 No

80

81

77

 Don’t know

0

0

0

 Missing values

0

1.2

0.87

Diabetes mellitus^c

 Yes

7.5

7.1

7.8

 No

92

91

92

 Don’t know

0.50

1.2

0

 Missing values

0

1.2

0

Herpes zoster^c

 Yes

18

20

16

 No

79

77

82

 Don’t know

2.0

1.2

2.6

 Missing values

1.0

2.4

0

Self-perceived health status^c

 Poor

0

0

0

 Fair

9.0

12

7.0

 Good

64

64

64

 Very good

21

15

25

 Excellent

4.0

7.1

1.7

 Missing values

2.0

2.4

1.7

Ever vaccinated against influenza^c

 Yes

78

80

74

 No

21

17

24

 Don’t know

1.0

2.4

0

 Missing values

1.5

1.2

1.7

 WBC count [x 10⁹L]

(normal values)

6.66 ± 1.70

6.91 ± 1.83

6.48 ± 1.59

(3.5–11)

(3.5–11)

 Neutrophils [x 10⁹L]

(normal values)

4.03 ± 1.42

4.18 ± 1.55

3.93 ± 1.30

(2.0–7.0)

(2.0–7.0)

 Monocytes [x 10⁹L]

(normal values)

0.58 ± 0.17

0.57 ± 0.16

0.59 ± 0.17

(0.2–1.0)

(0.2–1.0)

 Lymphocytes [x 10⁹L]

(normal values)

1.89 ± 0.89

1.97 ± 0.69

1.83 ± 1.01

(1.0–3.0)

(1.0–3.0)

 Erythrocytes [x 10¹²L]

(normal values)

4.81 ± 0.40

4.70 ± 0.39

4.89 ± 0.40

(3.90–5.00)

(4.32–5.72)

 Haemoglobin [g/dL]

(normal values)

14.57 ± 1.26

13.95 ± 1.04

15.02 ± 1.22

(12.0–15.5)

(13.5–17.5)

 Thrombocytes [tsd/μL]

(normal values)

225.6 ± 54.1

256.2 ± 53.6

202.8 ± 42.0

(150–450)

(150–450)

CMV-specific IgG

 Negative

45

44

46

 0.45–5.00 IU/mL

6.0

3.5

7.8

 5.00–15.00 IU/mL

25

26

24

 > 15.00 IU/mL

24

27

23