Effectiveness of palivizumab immunoprophylaxis in preterm infants against respiratory syncytial virus disease in Qatar

Figures & data

Table 1 Subjects characteristics during the December 1 to March 31, 2011–2012 RSV season

Variables	Total subjects (N=429)	<32 weeks (N=225 [52.4%])	32–35 weeks (N=204 [47.6%])
GA, weeks (mean ± SD)	30.9±2.8	28.7±2.08	33.3±1
Female	229 (53.4)	115 (51.1)	114 (55.9)
Male	200 (46.6)	110 (48.9)	90 (44.1)
Birth weight, g (mean ± SD)	1589.1±484.8	1268.9±354.1	1945±342
Age at enrollment
≤3 months	278 (64.8)	101 (44.9)	177 (86.8)
4–6 months	67 (15.6)	48 (21.3)	19 (9.3)
7–12 months	60 (14)	52 (23.1)	8 (3.9)
>12 months	24 (5.6)	24 (10.7)	0 (0)
Multiple births	218 (50.8)	105 (46.7)	113 (55.4)
BPD	80 (18.6)	77 (34.2)	3 (1.5)
CHD	49 (11.5)	39 (17.6)	10 (4.9)
Presence of siblings	322 (77.9)	165 (77.5)	157 (78.5)
Sibling in school	168 (41.8)	89 (43)	79 (40.5)
Parental asthma	35 (8.2)	16 (7.7)	19 (9.7)
Sibling history of asthma	36 (8.4)	22 (10.7)	14 (7.3)
Mother’s age, years (mean ± SD)	30.6±5.45	30.4±5.17	30.9±5.7
Childcare center exposure	8 (1.9)	2 (1)	6 (3.1)
Smoke exposure	139 (32.4)	69 (33.3)	70 (35.9)

Note: Data presented as n (%) unless otherwise stated.

Abbreviations: BPD, bronchopulmonary dysplasia; CHD, congenital heart disease; GA, gestational age; RSV, respiratory syncytial virus.

Table 2 RSV-related respiratory disease characteristics of hospitalized infants during the December 1 to March 31, 2011–2012 season

Variables	<32 weeks (N=225 [52.4%])	32–35 weeks (N=204 [47.5%])	Total subjects (N=429)
Compliance	205 (91.1)	199 (97.5)	404 (94.2)
Subjects hospitalized	23/205 (11.2)	11/199 (5.5)	34/404 (8.4)
RSV hospitalized subjects	4/205 (2)	3/199 (1.5)	7/404 (1.7)
RSV positive among hospitalized subjects	4/23 (17.4)	3/11 (27.3)	7/34 (20.6)
RSV-related length of stay, days (mean ± SD)	13.2±7.5	4.6±1.15	9±7.04
RSV-related PICU admission	1/4 (25)	0 (0)	1/7 (14.3)
Age at 1st dose of palivizumab for RSV hospitalized subjects, months (mean ± SD)	2.3±2.5	0.4±0.1	1.5±2
Age at hospital admission, months (mean ± SD)	3.2±2.6	1.8±0.8	2.6±2

Note: Data presented as n (%) unless otherwise stated.

Abbreviations: PICU, pediatric intensive care unit; RSV, respiratory syncytial virus.

Table 3 Characteristics of infants with RSV hospitalization during December 1 to March 31, 2011–2012 season

Risk factor	Number of infants with RSV hospitalization/total (%)
All infants	7/404 (1.7)
GA
<32	4/205 (2)
32–35	3/199 (1.5)
Male	4/7 (57.1)
Female	3/7 (42.9)
Age at enrollment
≤3 months	6/278 (2.2)
4–6 months	1/67 (1.5)
7–12 months	0/60
≥12 months	0/24
Multiple births	2/218 (0.9)
BPD	2/80 (2.5)
CHD	2/49 (4.1)
Presence of siblings	6/322 (1.9)
Sibling in school	3/168 (1.8)

Abbreviations: BPD, bronchopulmonary dysplasia; CHD, congenital heart disease; GA, gestational age; RSV, respiratory syncytial virus.

Table 4 Rate of hospitalization due to RSV infection across seasons from November 1 to March 31 (2009–2010 vs 2010–2011 vs 2011–2012 seasons)

Variables	2009–2010	2010–2011	2011–2012
Number of preterm infants	187	246	429
GA, weeks (mean ± SD)	28.9±2.6	30.6±2.8	30.9±2.8
<32	148 (79.1)	123 (50)	225 (52.4)
32–35	39 (20.8)	123 (50)	204 (47.5)
Male	101 (54)	129 (52.4)	200 (46.6)
Female	86 (46)	117 (47.6)	229 (53.4)
Age at enrollment, months (mean ± SD)	5.1±4.8	4.3±4.2	3.4±4.2
Birth weight, g (mean ± SD)	1266.3±393.3	1533.6±485	1589.1±484.8
Multiple births	71 (38)	90 (36.6)	218 (50.8)
BPD	79 (42.2)	53 (21.5)	80 (18.6)
CHD	35 (18.7)	28 (11.4)	49 (11.5)
Subjects hospitalized	18 (16.7)	16 (7)	34 (8.5)
<32	12 (66.7)	13 (81.2)	24 (70.5)
32–35	6 (33.3)	3 (18.7)	10 (29.4)
RSV hospitalized subjects	4/18 (22.2)	3/16 (18.7)	7/34 (20.6)
<32	2 (50)	3 (100)	4 (57.1)
32–35	2 (50)	0 (0)	3 (42.9)
Rate of compliance	108 (57.7)	228 (92.6)	404 (94.2)
Rate of hospitalization due to RSV infection	4/108 (3.7)	3/228 (1.3)	7/404 (1.7)

Note: Data presented as n (%) unless otherwise stated.

Abbreviations: BPD, bronchopulmonary dysplasia; CHD, congenital heart disease; GA, gestational age; RSV, respiratory syncytial virus.