Moderate influenza vaccine effectiveness with variable effectiveness by match between circulating and vaccine strains in Australian adults aged 20–64 years, 2007–2011

Influenza and Other Respiratory Viruses

Heath A. Kelly¹  Sheena G. Sullivan²  Kristina A. Grant¹ 

[1] Victorian Infectious Diseases Reference Laboratory, Melbourne, Vic., Australia;WHO Collaborating Centre for Reference and Research on Influenza, Melbourne, Vic., Australia.

关键词: influenza;    influenza vaccine;    influenza‐like illness;    vaccine effectiveness;   

DOI  :  10.1111/irv.12018

来源: Wiley

【 摘 要 】

Abstract

Please cite this paper as: Kelly et al. Moderate influenza vaccine effectiveness with variable effectiveness by match between circulating and vaccine strains in Australian adults aged 20–64 years, 2007–2011. Influenza and Other Respiratory Viruses DOI:10.1111/irv.12018.

Background  Influenza vaccines are licensed annually based on immunogenicity studies. We used five sequential years of data to estimate influenza vaccine effectiveness (VE), the critical outcome in the field.

Methods  Between 2007 and 2011, we performed annual prospective test-negative design case–control studies among adults aged 20–64 years recruited from sentinel general practices in the Australian state of Victoria. We used PCR-confirmed influenza as the endpoint to estimate influenza VE for all years. We compared annual VE estimates with the match between circulating and vaccine strains, determined by haemagglutination inhibition assays.

Results  The adjusted VE estimate for all years (excluding 2009) was 62% (95% CI 43, 75). By type and subtype, the point estimates of VE by year ranged between 31% for seasonal influenza A(H1N1) and 88% for influenza A(H1N1)pdm09. In 2007, when circulating strains were assessed as incompletely matched, the point estimate of the adjusted VE against all influenza was 58%. The point estimate was 59% in 2011 when all strains were assessed as well matched.

Conclusion  Trivalent inactivated vaccines provided moderate protection against laboratory-confirmed influenza in adults of working age, although VE estimates were sensitive to the model used. VE estimates correlated poorly with circulating strain match, as assessed by haemagglutination inhibition assays, suggesting a need for VE studies that incorporate antigenic characterization data.

【 授权许可】

Unknown   
© 2012 John Wiley & Sons Ltd