Table 3 Above: Results, secondary attack rates and odds ratios for studied exposure variables (aOR given where applicable). Table key: UVA = univariable analysis; MVA = multivariable analysis; SAR = secondary attack rate; OR = odds ratio; aOR = adjusted odds ratio; CI = Confidence Interval; Ref. = reference row for that section. Blank results space implies data not applicable; flight duration and proximity were not included in the multivariable regression model. Explanation of seating configuration assumptions in methods

Number of index cases on plane

1

460,837

3,206

0.69

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

2–3

170,528

1,534

0.89

1.29

1.22, 1.37

< 0.001

1.29

1.20, 1.40

< 0.001

1.17

1.05, 1.29

0.003

1.17

1.04, 1.31

0.01

> 4

31,195

549

1.73

2.53

2.31, 2.77

< 0.001

2.53

2.23, 2.87

< 0.001

1.59

1.27, 1.99

< 0.001

1.59

1.24, 2.06

< 0.001

Number of symptomatic index cases on plane

0

245,151

1,578

0.64

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

1

304,176

2,375

0.77

1.21

1.14, 1.29

< 0.001

1.21

1.12, 1.31

< 0.001

1.16

1.07, 1.26

< 0.001

1.16

1.06, 1.27

0.001

2–3

95,590

987

1.02

1.60

1.48, 1.74

< 0.001

1.60

1.45, 1.78

< 0.001

1.22

1.06, 1.40

0.004

1.22

1.04, 1.43

0.01

> 4

17,643

349

1.94

3.07

2.73, 3.45

< 0.001

3.07

2.61, 3.62

< 0.001

1.85

1.40, 2.44

< 0.001

1.85

1.32, 2.58

< 0.001

Vaccination status of contacts

Not vaccinated

50,034

604

1.19

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

Partially vaccinated

18,725

166

0.88

0.73

0.62, 0.87

< 0.001

0.73

0.62, 0.87

< 0.001

0.75

0.63, 0.89

< 0.001

0.75

0.63, 0.89

< 0.001

Fully vaccinated

331,447

2,374

0.71

0.59

0.54, 0.65

< 0.001

0.59

0.53, 0.66

< 0.001

0.52

0.47, 0.57

< 0.001

0.52

0.46, 0.57

< 0.001

Unknown

262,354

2,145

0.81

0.68

0.62, 0.74

< 0.001

0.68

0.60, 0.76

< 0.001

Age group of

contact (years)

0–24

82,262

543

0.66

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

Ref.

25–39

212,538

1,406

0.66

1.00

0.91, 1.11

> 0 0.9

1.00

0.90, 1.12

> 0.9

1.05

0.93, 1.20

0.4

1.05

0.93, 1.19

0.4

40–65

295,008

2,707

0.91

1.39

1.27, 1.53

< 0.001

1.39

1.24, 1.55

< 0.001

1.49

1.32, 1.68

< 0.001

1.49

1.32, 1.68

< 0.001

> 65

72,752

633

0.87

1.32

1.18, 1.48

< 0.001

1.32

1.14, 1.53

< 0.001

1.49

1.27, 1.74

< 0.001

1.49

1.27, 1.74

< 0.001

Flight duration

<= 2 h

29,168

164

0.56

Ref.

Ref.

Ref.

> 2 h

34,117

228

0.66

1.19

0.97, 1.46

0.1

Proximity

(seated within two rows)

Estimated 3 × 3 configuration

1,364

189

Ref.

Ref.

Ref.

Observed

1,240

313

1.82

1.50, 2.22

< 0.001

Estimated 3 × 4 × 3 configuration

1,427

126

Ref.

Ref.

Ref.

Observed

1,240

313

2.86

2.29, 3.56

< 0.001