Invasive pneumococcal disease in non-Indigenous people in north Queensland, 2001-2009

Med J Aust. 2010 Oct 4;193(7):392-6. doi: 10.5694/j.1326-5377.2010.tb03965.x.

Abstract

Objective: To compare trends in invasive pneumococcal disease (IPD) in non-Indigenous people in north Queensland before and after the introduction of funded pneumococcal vaccines, and to examine the proportion of cases that occurred after vaccine roll-out that could be vaccine-preventable.

Design, setting and participants: In 2005, a 7-valent pneumococcal conjugate vaccine (7vPCV) for non-Indigenous children and a 23-valent pneumococcal polysaccharide vaccine (23vPPV) for non-Indigenous adults aged ≥ 65 years were made freely available. Trends in IPD in the non-Indigenous estimated resident population in north Queensland (about 581 850 in 2006) were compared between the 4 years before (2001-2004) and after (2006-2009) the vaccines were rolled out.

Main outcome measures: Incidences and serotypes of IPD in non-Indigenous people.

Results: After the introduction of the vaccines, there were significant declines for all ages in the average annual incidence of IPD (- 34%; P < 0.05) and 7vPCV serotype IPD (- 77%; P < 0.05). In children aged < 5 years, there was a 91% decline in the incidence of 7vPCV serotype IPD (P < 0.05); in adults aged 15-64 years and ≥ 65 years there were 62% and 77% declines, respectively, in 7vPCV and 23vPPV common-serotype IPD (P < 0.05). There was a 188% increase in 23vPPV-only serotype IPD in adults aged 15-64 years (P < 0.05), whereas there was no significant change in adults aged ≥ 65 years. Serotype 19A was the most frequently identified serotype in 2006-2009, causing 19% of all IPD in those 4 years.

Conclusions: There is circumstantial evidence that 7vPCV has had a powerful indirect effect in preventing IPD in adults in north Queensland; 23vPPV may have had a direct effect in adults aged ≥ 65 years. It is likely that with combined direct and indirect effects, newer conjugate vaccines could prevent more IPD than could be prevented with the two current vaccines.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Child, Preschool
  • Humans
  • Middle Aged
  • Pneumococcal Infections / epidemiology*
  • Pneumococcal Infections / immunology
  • Pneumococcal Infections / prevention & control
  • Pneumococcal Vaccines / immunology*
  • Queensland / epidemiology
  • Serotyping
  • Vaccination
  • Vaccines, Conjugate / immunology

Substances

  • Pneumococcal Vaccines
  • Vaccines, Conjugate