Changing epidemiology of invasive pneumococcal disease due to vaccine

January 01, 0001

Changing epidemiology of invasive pneumococcal disease due to vaccine

The aim of this study by researchers from Australia was to evaluate trends in the incidence and serotype profile of invasive pneumococcal disease (IPD) in Australian children under 2 years of age after the introduction of the 7-valent pneumococcal conjugate vaccine (7vPCV). Overall incidence of IPD decreased by 74% in all children less than 2 years of age between 2002 and 2007. While the incidence of IPD caused by 7vPCV serotypes decreased significantly among both Indigenous and non-Indigenous children, the incidence of non-7vPCV serotype IPD increased significantly in non-Indigenous children (from 9.7 to 15.7 per 100 000). Compared with a pre-vaccination period (2002-2004), the 2007 incidence of serotype 19A IPD in non- Indigenous children increased significantly (from 2.7 to 8.6 per 100 000). In 2007, 19A was the predominant serotype causing IPD (37.7%) in all children aged less than 2 years.

Overall incidence of IPD decreased by 74% in all children less than 2 years of age between 2002 and 2007. While the incidence of IPD caused by 7vPCV serotypes decreased significantly among both Indigenous and non-Indigenous children, the incidence of non-7vPCV serotype IPD increased significantly in non-Indigenous children (from 9.7 to 15.7 per 100 000). Compared with a pre-vaccination period (2002-2004), the 2007 incidence of serotype 19A IPD in non- Indigenous children increased significantly (from 2.7 to 8.6 per 100 000). In 2007, 19A was the predominant serotype causing IPD (37.7%) in all children aged less than 2 years.

The researchers concluded: "The overall incidence of IPD decreased from 2002 to 2007, primarily driven by a reduction in IPD caused by 7vPCV serotypes. However, this was partially offset by a significant increase in the incidence of IPD caused by non-7vPCV serotypes, particularly 19A, in non- Indigenous children."

This can be overcome, supposedly, with covering more serotypes with the vaccine.


For the full abstract, click here.

MJA 194(3):116-120, 7 February 2011
© The Medical Journal of Australia 2011
Changing epidemiology of invasive pneumococcal disease in Australian children after introduction of a 7-valent pneumococcal conjugate vaccine. Scott R Williams, Paul J Mernagh, Michael H T Lee and Jonathan T Tan. Correspondence to Scott Williams: [email protected]

Category: B. Blood/Blood Forming Organs/Immune Mechanisms. Keywords: epidemiology, invasive, pneumococcal disease, conjugate, vaccine, incidence trends, journal watch.
Synopsis edited by Dr Stephen Wilkinson, Melbourne, Australia. Posted on Global Family Doctor 25 February 2011

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