Table 4 Logistic regression analysis on associated risks of having a positive serological test at baseline^a

Age (years)

N/A

0.98

0.96

–

1.0

0.012

0.97

0.95

–

0.99

0.009

Municipality

South Mexico City

39/171

26.4

Ref

Ref

North Mexico City

24/91

26.4

1.2

0.7

–

2.2

0.561

1.2

0.6

–

2.4

0.566

East Mexico City

42/133

31.6

1.7

1.0

–

2.8

0.061

1.7

0.9

–

3.0

0.092

West Mexico City

41/148

27.7

1.4

0.8

–

2.4

0.213

1.8

1.0

–

3.3

0.040

State of Mexico

70/190

36.8

2.1

1.3

–

3.4

0.003

2.1

1.2

–

3.5

0.007

Other^c

16/60

26.7

1.3

0.6

–

2.6

0.456

1.1

0.5

–

2.3

0.887

Comorbidities^d

No

167/581

28.7

Ref

Ref

Yes

66/217

30.4

1.0

0.7

–

1.5

0.867

1.2

0.8

–

1.8

0.424

Type of COVID-19 vaccine

Non-vaccinated

81/277

29.2

Ref

Ref

BNT162b2 (Pfizer/BioNTech)

30/14

24.2

0.6

0.4

–

1.0

0.060

0.9

0.5

–

1.7

0.742

AZD1222 (AstraZeneca)

84/256

32.8

1.1

0.7

–

1.6

0.710

1.5

0.9

–

2.3

0.095

Ad5-nCoV (Cansino)

6/26

23.1

0.8

0.3

–

2.1

0.629

1.1

0.4

–

3.2

0.864

Gam-COVID-Vac (Sputnik-V)

19/75

25.3

0.7

0.4

–

1.2

0.189

1.0

0.5

–

1.9

0.919

CoronaVac (Sinovac)

8/16

50.0

3.4

1.0

–

11.6

0.052

26

2.9

–

227.7

0.004

Meetings without social distancing

No

132/474

27.9

Ref

Ref

Yes

101/324

31.2

1.2

0.9

–

1.7

0.254

1.7

1.2

–

2.5

0.005

Use of public transport

No

87/351

24.8

Ref

Ref

Subway

103/329

31.3

1.3

0.9

–

1.9

0.103

1.1

0.7

–

1.6

0.659

Taxi/Uber

4/24

20.8

0.8

0.3

–

2.2

0.623

0.1

0.0

–

1.1

0.067

Other^e

38/94

40.4

2.3

1.3

–

3.8

0.002

2.1

1.2

–

3.7

0.012

Drug use^f

No

217/710

30.6

Ref

Ref

Yes

14/85

16.5

0.5

0.2

–

0.8

0.011

0.3

0.1

–

0.5

0.001

CD4 category (cells/mm³)^g

 < 200

12/63

19.1

Ref

Ref

200–499

136/434

31.3

2.0

1.0

–

4.0

0.043

2.3

1.1

–

5.1

0.032

 ≥ 500

84/299

28.1

1.8

0.9

–

3.6

0.100

2.3

1.0

–

5.1

0.040