. Author manuscript; available in PMC: 2018 Nov 29.

Published in final edited form as: Clin Infect Dis. 2017 Nov 29;65(12):1977–1983. doi: 10.1093/cid/cix724

Table 4.

Effectiveness of Maternal Tdap Vaccination at Preventing Infant Pertussis Hospitalizations, by Timing of Vaccination

	Cases		Controls		Multivariable VE^a, % (95% CI)
Total	157	%	336	%
Unvaccinated	76	48.4	109	32.4	REFERENCE
Before pregnancy	16	10.2	46	13.7	76.2 (37.2 – 91.0)
1^st or 2^nd trimester	2	1.3	20	6.0	91.4 (24.8 – 99.0)
3^rd trimester	6	3.8	47	14.0	90.5 (65.2 – 97.4)
After pregnancy	57	36.3	114	33.9	32.5 (−23.5 – 63.1)

Abbreviations: CI, confidence interval; VE, vaccine effectiveness

The following variables were included in the final model: household size >2 persons, maternal education, household member with pertussis diagnosis, and infant age (weeks).