TABLE 1.

Serum from PCR-positive cases 4 to 9 weeks after symptom onset^a

Sample	Sex/age (yr)b	CT value	Primary vaccine series	aP boost	Date (mo/day/yr) of:		Time from symptom onset to sample (wk)	ACT ELISA (U/ml)	TNA (%)d	PT ELISA (U/ml)
					Last vaccination	Approx symptom onsetc
V002	F/14	26.3	5 aP	+	03/14/11	08/25/14	8	47.3	100	300
V003	M/17	HCe	5 aP	+	08/14/08	08/11/14	4	44.8	100	640
V006	F/18	28.1	5 ap	+	07/08/08	05/15/15	6	4.8	0	24.1
V007	M/16	14.0	5 aP	+	07/20/10	05/28/15	4	63.9	100	464
V008	F/17	27.8	5 aP	+	08/08/11	05/28/15	5	30.5	85.4	184
V009	M/12	20.6	5 aP		08/06/08	05/05/15	8	93.7	100	215
V010	M/13	23.2	5 aP	+	10/14/12	06/01/15	5	156	100	73.8
V011	M/22	34.5	3 wP, 2 aP	+	04/27/07	07/26/15	4	30.6	95.5	413
V012	M/15	29.0	5 aP	+	08/30/10	05/07/15	9	45.5	85.4	803
V013	F/18	19.5	5 ap	+	07/10/08	06/17/15	9	23.6	69.8	329
V014	M/13	32.9	5 aP	+	08/23/13	07/01/15	7	9.8	19.3	94.1
V015	F/15	32.7	5 aP	+	08/07/12	09/21/15	5	21.7	60.4	276
V016	F/14	36.2	5 aP	+	01/18/12	09/20/15	6	54.3	97.4	170
V017	F/15	17.5	5 aP	+	01/14/11	10/23/15	6	44.4	98.0	290
V018	M/15	31.9	5 aP	+	06/28/11	10/22/15	7	0.71	0	1,404
V019	F/17	29.8	5 aP	+	08/18/09	11/01/15	5	30.0	81.1	563
V020	M/17	27.5	5 aP	+	04/23/10	11/14/15	4	3.28	0	293
V021	M/14	32.1	5 aP	+	02/13/13	10/12/15	7	0.75	0	1,040

^aBolded values are considered positive (see Table 2 for data from normal controls). Data represent the mean of the results from each sample tested in duplicate (ELISA) or triplicate (TNA).

^bF, female; M, male.

^cAt onset of clinical illness, all subjects reported symptoms consistent with pertussis.

^dPercent toxin neutralization using a 1:50 final serum dilution, as described in Materials and Methods.

^eHC, sample was from a household contact of subject V002 with clinical symptoms of pertussis.