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Contact
WHO Collaborating Centre for Reference and Research on Influenza (VIDRL)
Peter Doherty Institute for Infection and Immunity
792 Elizabeth Street
Melbourne VIC 3000 Australia

T +61 3 9342 9300
F +61 3 9342 9329
whoflu@influenzacentre.org


Epidemiology

A/Prof Sheena Sullivan
Senior Epidemiologist
Adjunct Assistant Professor, Department of Epidemiology, University of California, Los Angeles
Adjunct Associate Professor, Centre for Epidemiology and Biostatistics, The University of Melbourne
Visiting Research Fellow, School of Population Health, The University of Adelaide


Email: sheena.sullivan@influenzacentre.org


Research Interests
Influenza viruses undergo frequent antigenic changes and thus influenza vaccination in one season may no longer confer protection in a subsequent season. Moreover, the severity, timing and strains circulating may differ across seasons. Thus, there is a need to estimate influenza vaccine effectiveness on an annual basis to better understand the protection conferred by the vaccine. In recent years, there has been a dramatic increase in the number of countries reporting annual influenza vaccine effectiveness estimates using test-negative design studies. In these studies, patients presenting with influenza-like illness are recruited into a surveillance programme, swabbed and tested for influenza. Vaccination status is recorded and those testing positive are compared with those testing negative to obtain an influenza vaccine effectiveness estimate. Such surveillance networks operate in Australia and the epidemiology group has been working with these networks to make estimates of vaccine effectiveness and understand methodological issues in the study design used. We have also been working with colleagues at the University of Hong Kong to validate the test-negative design and characterise its theoretical basis.

A particular, poorly understood problem with influenza vaccines is that repeated, annual vaccination may not confer the protection expected and may in fact reduce vaccine effectiveness. The epidemiology group has conducted studies among hospital workers – a highly vaccinated population – to study the immunological consequences of repeated vaccination.

Finally, the burden of influenza is a topic of intense interest with a push from the WHO to understand the global burden. The epidemiology group has been working with groups in the Western Pacific Region and within Australia to estimate the burden of influenza.  

Research projects
  1. Understanding the validity of the test-negative design for studies of influenza vaccine effectiveness (with School of Public Health, University of Hong Kong).
  2. Pooling influenza vaccine effectiveness surveillance data across Australia (with Australian Sentinel Practices Research Network and Victorian Sentinel Practitioners Influenza Surveillance).
  3. Understanding the role of vaccination in genetic drift.
  4. Use of a discrete choice experiment to determine the factors considered, and the trade-offs made, by health care workers when deciding whether to receive the seasonal influenza vaccine (with Epidemiology Unit, VIDRL).
  5. Estimation of the burden of influenza in Australia

Key publications
Li L, Wong JY, Wu P, Bond HS, Lau EHY, Sullivan SG, Cowling BJ. Heterogeneity in estimates of the impact of influenza on population mortality: a systematic review. Am J Epidemiol (in press), doi: 10.1093/aje/kwx270 PubMed link

Leung VKY, Carolan LA, Worth LJ, Harper SA, Peck H, Tilmanis D, Laurie KL, Slavin MA, Sullivan SG. Influenza vaccination responses: Evaluating impact of repeat vaccination among health care workers. Vaccine 2017;35:2558-68. doi: 10.1016/j.vaccine.2017.03.063. PubMed link

Sullivan SG, Tchetgen Tchetgen E, Cowling BJ. Theoretical basis of the test-negative study design for assessment of influenza vaccine effectiveness.. Am J Epidemiol 2016;184(5):345-53. doi: 10.1093/aje/kww064. PubMed link

Sullivan SG, Feng S, Cowling BJ. Influenza vaccine effectiveness: potential of the test-negative design. A systematic review. Expert Rev Vaccines 2014;13:1571-91. doi: 10.1586/14760584.2014.966695 PubMed link

Detels R, Sullivan SG, Tan CC, editors. Public Health in Asia: Challenges and Opportunities in the 21st Century. Berkeley: University of California Press, 2012.


All relevant publications (PubMed listing)
All publications from the Centre

Antivirals and animal influenzas group
Early immune response group

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