159 / 280
(in 2005) with 50 cases after vaccine
introduction (in 2009), no differences
were observed in frequency of chest
radiographs on admission (100% in
2005, 98% in 2009). Chronic conditions
(mainly asthma, prematurity, or neu-
rologic disease) were found in 36% of
children in 2005 and 31% in 2009 (
P
=
.82). The clinical severity of pneumonia,
measured using mean C-reactive pro-
tein, oxygen saturation, and need for
oxygen or intensive care, was compa-
rable in 2005 and in 2009 (data not
shown).
Empyema
For children
,
2 years old there was
a nonsigni
fi
cant increased incidence of
hospitalization for empyema in the
period after compared with the period
before PCV7 and PCV13 vaccination
(4.4 vs 2.5 per 100 000 person-years;
RR = 1.78; 95% CI, 0.55
–
6.63;
P
= .42)
(Table 1).
Hospitalization for Control
Diagnosis
Pyelonephritis was used as an indica-
tor disease for general hospitalization
trends during the study period. There
was a slight increase in hospitalizations
during the study period in the age group
0 to
,
2 years but not among children
aged 2 to
,
5 years (Table 1). However,
in the time trend analysis (Fig 1) the
month-to-month incidence remained
stable in the prevaccination and post-
vaccination period for both age groups
(Fig 1 and Table 2).
The incidence of hospitalizations for
asthma and obstructive bronchitis
remained stable during the study pe-
riod (Table 1). However, the incidence
of hospitalization for RSV infections
and viral pneumonia increased sig-
ni
fi
cantly in children
,
2 years old
between the prevaccination and post-
vaccination periods (RR = 1.37; 95%
CI, 1.29
–
1.46;
P
,
.001 and RR = 1.46;
95% CI, 1.08
–
1.97;
P
= .01, respectively)
(Table 1).
DISCUSSION
To our knowledge this is the
fi
rst study
showing that introduction of PCV7 and
PCV13 in the childhood vaccination
program signi
fi
cantly reduces hospi-
talizations for sinusitis in children
,
5
years of age. We also found a signi
fi
-
cant reduction in hospitalization rates
for pneumonia in children
,
5 years
old. However, there was an increase in
empyema in children
,
2 years of age
in the postvaccination compared with
the prevaccination period, but this was
not statistically signi
fi
cant.
TABLE 1
Number of Hospitalizations and Incidence of Pneumonia, Sinusitis, Empyema, Pyelonephritis, Asthma and Obstructive Bronchitis, RSV
Infection, and Viral Pneumonia in Children 0 to
,
18 y Before and After Sequential PCV7 and PCV13 Introduction in Stockholm
Diagnosis
No. of Cases
IncidenceRateper100 000 Person-Years
RR (95% CI)
P
Before July
2003
–
June 2007
After July
2008
–
June 2012
Before July
2003
–
June 2007
After July
2008
–
June 2012
Pneumonia
0
–
,
2 y
914
836
450
366
0.81 (0.74
–
0.89)
,
.001
2
–
,
5 y
687
694
250
212
0.85 (0.76
–
0.94)
.002
5
–
,
18 y
604
683
51
56
1.10 (0.99
–
1.23)
.09
Sinusitis
0
–
,
2 y
142
55
70
24
0.34 (0.25
–
0.47)
,
.001
2
–
,
5 y
70
60
25
18
0.72 (0.51
–
1.02)
.06
5
–
,
18 y
82
98
7
8
1.16 (0.87
–
1.56)
.31
Empyema
0
–
,
2 y
5
10
2.5
4.4
1.78 (0.55
–
6.63)
.42
2
–
,
5 y
5
10
1.8
3.1
1.68 (0.52
–
6.26)
.49
5
–
,
18 y
11
19
0.9
1.6
1.68 (0.80
–
3.53)
.17
Pyelonephritis
0
–
,
2 y
598
757
294
331
1.13 (1.01
–
1.25)
.03
2
–
,
5 y
123
156
45
48
1.06 (0.84
–
1.35)
.61
5
–
,
18 y
167
233
14
19
1.36 (1.11
–
1.66)
.002
Asthma and obstructive bronchitis
0
–
,
2 y
2136
2493
1051
1090
1.04 (0.98
–
1.10)
.21
2
–
,
5 y
709
902
258
275
1.07 (0.97
–
1.18)
.20
5
–
,
18 y
334
323
28
27
0.94 (0.81
–
1.10)
.44
RSV infection
0
–
,
2 y
1711
2647
842
1158
1.37 (1.29
–
1.46)
,
.001
2
–
,
5 y
58
137
21
42
1.98 (1.46
–
2.69)
,
.001
5
–
,
18 y
7
28
0.6
2.3
3.89 (1.66
–
10.56)
,
.001
Viral pneumonia
0
–
,
2 y
70
115
34
50
1.46 (1.08
–
1.97)
.01
2
–
,
5 y
42
60
15
18
1.20 (0.81
–
1.78)
.37
5
–
,
18 y
24
58
2.0
4.8
2.35 (1.46
–
3.78)
,
.001
PEDIATRICS Volume 134, Number 6, December 2014
137