Influenza Vaccine Effectiveness in Victoria, Australia (2007-2008)
Author Information
Author(s): Fielding James E, Grant Kristina A, Papadakis Georgina, Kelly Heath A
Primary Institution: Victorian Infectious Diseases Reference Laboratory
Hypothesis
What is the type- and subtype-specific effectiveness of the influenza vaccine in Victoria, Australia?
Conclusion
The study found that influenza vaccine effectiveness varied by year and subtype, with significant effectiveness against A/H3N2 in 2007 but not in 2008.
Supporting Evidence
- Vaccine effectiveness against A/H3N2 was 68% in 2007.
- Vaccine effectiveness against A/H1N1 and B was not statistically significant in 2007.
- In 2008, the adjusted VE against type B was 49%, but not significant.
- Overall, the study highlights the need for type- and subtype-specific assessments of influenza vaccine effectiveness.
Takeaway
This study looked at how well the flu vaccine worked in Victoria over two years, finding it was effective against some types of the flu but not others.
Methodology
The study used a test-negative case control design with patients presenting with influenza-like illness tested for influenza and their vaccination status recorded.
Potential Biases
Potential biases include ascertainment bias and the exclusion of cases from the clinical spectrum.
Limitations
The study had a low proportion of cases with strain typing results and did not control for chronic or co-morbid conditions.
Participant Demographics
Participants included patients with influenza-like illness from a sentinel surveillance network, with a majority being working-age adults.
Statistical Information
P-Value
0.004
Confidence Interval
95% CI, 32 to 85%
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
Want to read the original?
Access the complete publication on the publisher's website