Evaluating the impact of PCV-10 on invasive pneumococcal disease in Brazil: A time-series analysis

Figures & data

Figure 1. Number of invasive pneumococcal disease by year according to vaccine serotypes and age group. Brazil, 2008 to 2013.

Table 1. Distribution of PCV-10 and PCV-13 types by age groups before and after the introduction of PCV-10 in the immunization program. Brazil 2008 to 2013a.

	Before PCV-10 introduction		After PCV-10 introduction
Age Group	n/Total	%	n/Total	%	p-value	% of change
PCV-10 types^b	878/1,493	58.8	995/2,885	34.5	<0.001	−41.3
2-11 m	157/212	74.1	72/229	31.4	<0.001	−57.6
12-23 m	151/187	80.7	27/88	30.7	<0.001	−62.0
2-4 yrs	105/136	77.2	107/225	47.6	<0.001	−38.3
5-9 yrs	66/114	57.9	74/147	50.3	0.225	−13.1
10-17 yrs	65/107	60.7	63/167	37.7	<0.001	−35.4
18-39 yrs	137/307	44.6	218/619	35.2	0.006	−21.1
40-64 yrs	154/324	47.5	305/996	30.6	<0.001	−39.5
≥65 y yrs	43/106	40.6	129/414	31.2	0.067	−23.2
PCV-13 minus PCV-10 types^b	217/1,493	14.5	540/2,285	23.6	<0.001	+62.8
Non PCV-10 and non PCV-13 types^b	398/1,493	26.7	1350/2,885	46.8	<0.001	+75.3
NT/missing	31/1,524	2.0	69/2,954	2.3	0.453	+15.0

^aExcluded transition period (year 2010)

^bExcluded 189 missing age cases, 75 missing (18 from prevaccination, and 57 from postvaccination period), and 25 NT (13 from prevaccination, and 12 from postvaccination period) serotypes

Table 2. PCV-10 vaccination impact on invasive pneumococcal disease: time-series analysis, by age group. Brazil, 2008 to 2013.

Age group	Observed rates	Predicted rates	% of change	95% CI		p-value
2-23 m	11.7	20.9	−44.2	−72.5;	−15.8	0.000
2-11 m	19.1	29.2	−34.7	−58.9;	−10.4	0.002
12-23 m	5.4	13.8	−61.1	−82.7;	−39.6	0.000
2-4 yrs	4.4	3.9	+14.7	−85.7;	115.1	0.347
5-9 yrs	2.1	2.2	−4.7	−66.0;	56.7	0.660
10-17 yrs	1.4	1.3	+6.2	−72.9;	85.2	0.465
18-39 yrs	1.6	1.3	+18.9	1.1;	36.7	0.018
40-64 yrs	3.3	2.2	+52.5	24.8;	80.3	0.000
≥65 yrs	4.2	2.3	+79.3	62.1;	96.5	0.000

CI, confidence interval.

Figure 2. Observed (black and red) and predicted (blue) bimonthly rates of IPD by age group. Brazil, 2008 to 2013. IPD, invasive pneumococcal disease.