Effectiveness of 7-valent pneumococcal conjugate vaccine: A meta-analysis of post-marketing studies

Table 1 Summary of studies characteristics and results

Ref.	Country	Study period	Invasive pneumococcal disease definition	Main results
Albrich et al[25]	United States	1997-2004	Isolation of S. pneumoniae from sterile body fluid	1
Ampofo et al[26]	United States	1997-2010	Isolation of S. pneumoniae from sterile body fluid	The proportion of children younger than 2 yr with IPD decreased (54% vs 43% with respect to all serotypes and 56% vs 43% for vaccine serotypes), while the proportion of disease among children aged 2-4 slightly increased (27% vs 29% with respect to all and vaccine serotypes)
Aristegui et al[27]	Spain	1998-2003	Isolation of S. pneumoniae from sterile body fluid	1
Barricarte et al[28]	Spain	2001-2005	Isolation of S. pneumoniae from sterile body fluid	The overall effectiveness in reducing IPD was 31% (OR = 0.69, 95%CI: 0.37-1.27) and 88% (OR = 0.12, 95%CI: 0.02-0.91) for all serotypes and vaccine serotypes respectively
Benito-Fernández et al[29]	Spain	2000-2005	Isolation of S. pneumoniae from sterile body fluid	1
Ben-Shimol et al[30]	Israel	1989-2010	Isolation of S. pneumoniae from sterile body fluid	In 2009 and 2010, IPD incidence (due to vaccine serotypes) were 15.9 per 100000 and 5.4, per 100000 respectively (a 43% and 81% decrease compared to 2003-2007)
Bjornson et al[31]	Canada	2001-2005	Isolation of S. pneumoniae from sterile body fluid	1
Calbo et al[32]	Spain	1999-2004	Isolation of S. pneumoniae from sterile body fluid	The IPD incidence significantly decreased from 96.9 cases per 100000 person-years to 90.6 cases per 100000 person-years (7% reduction)
Carstairs et al[33]	United States	2000-2002	Isolation of S. pneumoniae from sterile body fluid	1
Casado-Flores et al[34]	Spain	2001-2006	Isolation of S. pneumoniae from sterile body fluid	1
CDC[35]	United States	1998-2005	Isolation of S. pneumoniae from sterile body fluid	1
De Serres et al[36]	United States	2001-2009	Isolation of S. pneumoniae from sterile body fluid	Effectiveness of PCV7 against IPD due to vaccine serotypes was 97% (95%CI: 92%-98%) among healthy children and 88% (95%CI: 78%-94%) among children with comorbid conditions. The incidence of IPD due to non-vaccine serotypes increased from 6.8 per 100000 (1998-1999) to 10.3 per 100000 in 2007 (51% increase)
De Wals et al[37]	Canada	2007-2010	Isolation of S. pneumoniae from sterile body fluid	A decrease in the frequency of IPD caused by vaccine serotypes was observed
Dias et al[38]	Portugal	1999-2004	Isolation of S. pneumoniae from sterile body fluid	1
Vestrheim et al[39]	Norway	2004-2008	Isolation of S. pneumoniae from sterile body fluid	1
Dubos et al[40]	France	2000-2005	Isolation of S. pneumoniae from sterile body fluid	A decrease of 82% (95%CI: 52%-95%) of cases was observed (from 8.9 cases per 100000 in 2001 to 1.8 per 100000 in 2005) in children < 2 yr
Fenoll et al[41]	Spain	1996-2001 2005-2006	Isolation of S. pneumoniae from sterile body fluid	A decrease of the incidence of IPD due to vaccine serotypes from 5.2 per 100000 in 1996-2001 to 2.4 per 100000 in 2005-2006 was observed
Flannery et al[42]	United States	1998-2002	Isolation of S. pneumoniae from sterile body fluid	1
Giele et al[43]	Australia	1996-2005	Isolation of S. pneumoniae from sterile body fluid	1
Schutze et al[44]	Arkansas	1998-2003	Isolation of S. pneumoniae from sterile body fluid	A decrease of IPD from 44.2 per 100000 person-years to 8.30 per 100000 person-years was observed in children < 2 yr
Guevara et al[45]	Spain	2001-2007	Isolation of S. pneumoniae from sterile body fluid	1
Haddy et al[46]	United States	1999-2002	Isolation of S. pneumoniae from sterile body fluid	1
Hanna et al[47]	Queensland	1999-2007	Isolation of S. pneumoniae from sterile body fluid	1
Hanquet et al[48]	Belgium	2002-2008	Isolation of S. pneumoniae from sterile body fluid	1
Harboe et al[49]	Denmark	2000-2008	Isolation of S. pneumoniae from sterile body fluid	In children < 2 yr, the overall incidence decreased from 54 to 23 cases per 100000 (IRR = 0.43, 95%CI: 0.29-0.62) and from 36.7 to 7.7 (IRR = 0.20, 95%CI: 0.09-0.38) for vaccine serotypes. A non-significant increase was observed in children aged 2-4 yr
Hennessy et al[50]	United States	1995-2003	Isolation of S. pneumoniae from sterile body fluid	1
CDC[51]	United States	1998-2003	Isolation of S. pneumoniae from sterile body fluid	A decrease of IPD due to vaccine serotypes from 80 cases per 100000 to 4.6 per 100000 was observed (decrease of 94% (95%CI: 92%-96%) from 1998-1999 to 2003
Hsu et al[52]	United States	1998-2005	Isolation of S. pneumoniae from sterile body fluid	1
Hsu et al[53]	United States	1990-1991 2001-2003	Isolation of S. pneumoniae from sterile body fluid	1
Hsu et al[54]	United States	2001-2007	Isolation of S. pneumoniae from sterile body fluid	IPD incidence was stable during the 6 yr period, although IPD due to vaccine serotypes decreased
Ingels et al[55]	Denmark	2000-2010	Isolation of S. pneumoniae from sterile body fluid	1
Wenger et al[56]	United States, Alaska	1986-2007	Isolation of S. pneumoniae from sterile body fluid	1
Johnson et al[57]	South Australia	2002-2009	Isolation of S. pneumoniae from sterile body fluid	1
Kellner et al[58]	Canada	1998-2007	Isolation of S. pneumoniae from sterile body fluid	1
Kyaw et al[59]	United States	1996-2004	Isolation of S. pneumoniae from sterile body fluid	1
Leal et al[60]	Alberta	1998-2010	Isolation of S. pneumoniae from sterile body fluid	1
Liao et al[61]	Taiwan	2000-2008	Isolation of S. pneumoniae from sterile body fluid	The overall incidence of IPD decreased by 33% (95%CI: 0%-72.2%)
Messina et al[62]	United States	1999-2001 2003-2005	Isolation of S. pneumoniae from sterile body fluid	1
Muñoz-Almagro et al[63]	Spain	1997-2006	Isolation of S. pneumoniae from sterile body fluid	1
Patrzalek et al[64]	Poland	2005-2010	Isolation of S. pneumoniae from sterile body fluid	1
Pérez et al[65]	Spain	1998-2008	Isolation of S. pneumoniae from sterile body fluid	1
Pérez-Trallero et al[66]	Spain	1996-2007	Isolation of S. pneumoniae from sterile body fluid	1
Pilishvili et al[67]	United States	1998-2007	Isolation of S. pneumoniae from sterile body fluid	1
Poehling et al[68]	United States	1997-2004	Isolation of S. pneumoniae from sterile body fluid	1
[69]	Canada	2002-2005	Isolation of S. pneumoniae from sterile body fluid	1
Ramani et al[70]	United States	1994-2001	Hospital discharges for IPD	A significant decrease was observed only for children aged < 1 yr (from 40 per 100000 to 23 per 100000 person years). All other age groups did not show a significant change in discharge rates for IPD
Rendi-Wagner et al[71]	Austria	2001-2007	Isolation of S. pneumoniae from sterile body fluid	1
Rodenburg et al[72]	Netherlands	2004-2008	Isolation of S. pneumoniae from sterile body fluid	1
Rückinger et al[73]	Germany	1997-2003 2007-2008	Isolation of S. pneumoniae from sterile body fluid	1
de Sevilla et al[74]	Spain	2007-2009	Isolation of S. pneumoniae from sterile body fluid	An increase of 44% of IPD (95%CI: 10%-89%) was shown
Shafinoori et al[75]	United States	1998-2004	Isolation of S. pneumoniae from sterile body fluid	A significant 68% and 70% decrease of IPD in children < 2 yr and aged 2 to 4 yr respectively was observed
Shah et al[76]	United States	1999-2003	Hospital discharges for IPD	A significant decrease from 12.03 per 100000 person-years in 1999 to 5.60 per 100000 person-years in 2003 was shown
Techasaensiri et al[77]	United States	1999-2008	Isolation of S. pneumoniae from sterile body fluid	The incidence of IPD significantly decreased in children < 2 yr
Tsai et al[78]	United States	1994-1999 2001-2004	Hospital discharges for pneumococcal meningitis	The average annualized rates of hospitalizations decreased from 7.7 per 100000 to 2.6 per 100000 in children < 2 yr and from 0.9 per 100000 to 0.5 per 100000 in children aged 2-4 (a reduction of 66%, 95%CI: 56.3%-73.5% and of 51.5%, 95%CI: 28.9%-66.9% respectively)
Tsigrelis et al[79]	United States	1995-2007	Isolation of S. pneumoniae from sterile body fluid	1
Tyrrell et al[80]	Canada	2000-2006	Isolation of S. pneumoniae from sterile body fluid	IPD due to vaccine serotypes decreased of 61% in children < 2 yr (from 96.7 per 100000 person-years to 25.8 per 100000 person-years) and of 57% in children from 2 to 4 yr (from 24.5 per 100000 person-years to 10.6 per 100000 person-years)
Van der Linden et al[81]	Germany	1997-2010	Isolation of S. pneumoniae from sterile body fluid	IPD incidence decreased from 2.4 per 100000 to 0.3 per 100000
Vestrheim et al[82]	Norway	2002-2007	Isolation of S. pneumoniae from sterile body fluid	1
Weatherholtz et al[83]	United States	1995-2006	Isolation of S. pneumoniae from sterile body fluid	Rates of IPD due to vaccine serotypes among children aged < 1 yr, 1-2 yr, and 2-5 yr decreased from 210, 263, and 51 cases per 100000 respectively in to 0 case per 100000
Whitney et al[84]	United States	1998-2001	Isolation of S. pneumoniae from sterile body fluid	1
Winters et al[85]	Canada	2002-2005	Isolation of S. pneumoniae from sterile body fluid	The incidence of IPD decreased from 54 per 100000 person-years to 16 per 100000 person-years (decrease of 70%). An even stronger decrease was observed in children < 1 yr, where the incidence decreased from 135 per 100000 to 15 per 100000 person-years (decrease of 89%)
Yildirim et al[86]	United States	2007-2010	Isolation of S. pneumoniae from sterile body fluid	IPD cases due to vaccine serotypes decreased

¹Studies included in the meta-analysis. IPD: Invasive pneumococcal disease; CDC: Centers for Disease Control and Prevention; IRR: Incidence rate ratio; PCV7: 7-valent pneumococcal conjugate vaccine; S. pneumoniae: Streptococcus pneumoniae.