Table 1.

Characteristics of Study Subjects at Enrollment

	Dose group
Characteristic	25 μg (n = 60)	49 μg (n = 60)
Age, mean years (range)	31.7 (20, 39)	31.2 (18, 39)
Trimester of gestation, %
Second (14–26 weeks)	57	72
Third (27–34 weeks)	43	28
Gestational age at enrollment, mean weeks (± standard deviation)	24.4 ± 6.2	22.6 ± 6.0
Race, %
White	85	80
Black	3	7
Asian	7	10
Other	5	3
Non-Hispanic ethnicity, %	88	93
Received 2008–2009 influenza vaccine,1 %	68	58
Received 2009–2010 influenza vaccine,2 %	28	27

NOTE. ¹The 2008–2009 influenza vaccine contained A/Brisbane/10/2007 (H3N2)-like, A/Brisbane/59/2007 (H1N1)-like, and B/Florida/4/2006-like strains.

²The 2009–2010 influenza vaccine contained A/Brisbane/10/2007 (H3N2)-like, A/Brisbane/59/2007 (H1N1)-like, and B/Brisbane/60/2008-like strains.