Table 1. DTP vaccine-specific antibody titers at 18 months of age in relation to demographic data.

		Vaccine-specific antibody titers
		IgG α-diphtheria toxin, IU ml−1		IgG α-tetanus toxoid, IU ml−1		IgG α-pertussis toxin, IU ml−1
	n	Median (range)	P-valuea	Median (range)	P-valuea	Median (range)	P-valuea
Gender
Girl	25	0.84 (0.08–3.3)	0.10	1.5 (0.33–3.5)	0.17	17 (3.0–200)	0.55
Boy	26	0.56 (0.09–1.7)		1.8 (0.17–5.2)		19 (4.6–120)
Delivery mode
Vaginal	43	0.66 (0.08–3.3)	0.62	1.8 (0.17–4.4)	0.75	19 (3.0–200)	0.37
C-section	8	1.1 (0.26–1.9)		1.8 (0.61–5.2)		15 (6.8–36)
Dairy farm
Yes	21	1.0 (0.08–2.9)	0.067	1.5 (0.17–3.5)	0.52	17 (4.6–70)	0.85
No	30	0.61 (0.09–3.3)		1.8 (0.33–5.2)		18 (3.0–200)

^aStatistical difference between the two groups of children, Mann–Whitney U-test.