Pandemic (H1N1) 2009 influenza vaccination coverage in Western Australia.

OBJECTIVE

To assess pandemic (H1N1) 2009 influenza vaccination coverage in Western Australians, up to 31 January 2010.

DESIGN, SETTING AND PARTICIPANTS: Vaccination data for Western Australians aged 10 years and older were obtained from two sources: the WA Pandemic Influenza Vaccination Database (PIVD; which collected reports of pandemic influenza vaccinations from vaccination providers statewide) for the period 30 September 2009 to 31 January 2010, and the WA Health and Wellbeing Surveillance System (HWSS; a continuous population-based telephone survey) for the period 1 December 2009 to 31 January 2010. Data from the PIVD was used to input vaccination coverage estimates for at-risk subpopulations not assessed in the HWSS interviews.

MAIN OUTCOME MEASURES

Vaccination coverage of Western Australians aged 10 years and older and of subgroups targeted by the national pandemic (H1N1) 2009 influenza vaccination campaign.

RESULTS

A total of 171,789 pandemic influenza vaccinations were reported to the PIVD by 31 January 2010 and 88% of these were administered by 1 December 2009. Based on HWSS data, vaccination coverage of persons aged 10 years and older was 14.5% (95% CI, 12.6%-16.6%) and of persons aged 18 years and older was 15.3% (95% CI, 13.3%-17.6%). Based on PIVD data, coverage in adults ranged from 10.3% in pregnant women to 52.8% in health care workers.

CONCLUSIONS

Our estimate of pandemic influenza vaccination coverage in the adult population of WA is comparable to the national estimate of 19%, but it did not reach levels considered sufficient to interrupt community transmission. Future influenza vaccination programs should target groups at increased risk of severe influenza, such as pregnant women.