Table 4.

Stage 3 Incidence of Laboratory-Confirmed Pertussis by Vaccine Received, by Duration and Type of Cough, and by Interval of Follow-Up^*

Cough and Duration	Vaccine Received^†	Interval
		1/10/95–31/10/96		1/11/96–31/10/97		1/11/97–31/10/98		Total Stage 3
		Cases	Rate^*	Cases	Rate^*	Cases	Rate^*	Cases	Rate^*
Any cough ≥7 d	SB	38	0.89	31	0.84	69	2.13	138	1.24
	CB	30	0.70	29	0.78	67	2.06	126	1.12
	DT	11	1.87	35	3.57	81	8.92	127	5.12
≥14 d spasmodic or ≥21 d any cough	SB	30	0.70	26	0.70	59	1.83	115	1.03
≥14 d spasmodic or ≥21 d any cough	CB	24	0.56	22	0.59	57	1.75	103	0.92
	DT	11	1.87	27	2.75	79	8.70	117	4.72
≥21 d spasmodic cough	SB	10	0.24	7	0.19	16	0.50	33	0.30
	CB	11	0.26	6	0.16	16	0.49	33	0.29
	DT	8	1.36	14	1.43	14	1.43	54	2.18

↵* Rates per 100 person-years of observation. Notification rates of pertussis for the corresponding birth cohorts and geographical areas in the general population per 1000 inhabitants were 8.9 in 1996, 6.5 in 1997, and 14.8 in 1998.
↵† SB indicates DTaP SB; CB, DTaP CB.