Impact of the national targeted Hepatitis A immunisation program in Australia: 2000-2014

Craig Thompson; Aditi Dey; Emily Fearnley; Benjamin Polkinghorne; Frank Beard

doi:10.1016/j.vaccine.2016.11.002

Impact of the national targeted Hepatitis A immunisation program in Australia: 2000-2014

Vaccine. 2017 Jan 3;35(1):170-176. doi: 10.1016/j.vaccine.2016.11.002. Epub 2016 Nov 18.

Authors

Craig Thompson¹, Aditi Dey², Emily Fearnley³, Benjamin Polkinghorne⁴, Frank Beard²

Affiliations

¹ National Centre for Immunisation Research and Surveillance, Sydney Children's Hospital Network, Westmead, NSW 2145, Australia; National Centre for Epidemiology and Population Health, Research School of Population Health, The Australian National University, Acton, ACT 2601, Australia. Electronic address: craig.thompson@health.nsw.gov.au.
² National Centre for Immunisation Research and Surveillance, Sydney Children's Hospital Network, Westmead, NSW 2145, Australia; University of Sydney, NSW 2006, Australia.
³ National Centre for Epidemiology and Population Health, Research School of Population Health, The Australian National University, Acton, ACT 2601, Australia.
⁴ Australian Government Department of Health, Canberra, ACT 2601, Australia.

PMID: 27876203
DOI: 10.1016/j.vaccine.2016.11.002

Abstract

In November 2005, hepatitis A vaccine was funded under the Australian National Immunisation Program for Aboriginal and Torres Strait Islander (Indigenous) children aged 12-24months in the targeted jurisdictions of Queensland, South Australia, Western Australia and the Northern Territory. We reviewed the epidemiology of hepatitis A from 2000 to 2014 using data from the Australian National Notifiable Diseases Surveillance System, the National Hospital Morbidity Database, and Australian Bureau of Statistics causes-of-death data. The impact of the national hepatitis A immunisation program was assessed by comparison of pre-vaccine (2000-2005) and post-vaccine time periods (2006-2014), by age group, Indigenous status and jurisdiction using incidence rate ratios (IRR) per 100,000 population and 95% confidence intervals (CI). The national pre-vaccine notification rate in Indigenous people was four times higher than the non-Indigenous rate, and declined from 8.41 per 100,000 (95% CI 5.03-11.79) pre-vaccine to 0.85 per 100,000 (95% CI 0.00-1.99) post-vaccine, becoming similar to the non-Indigenous rate. Notification and hospitalisation rates in Indigenous children aged <5years from targeted jurisdictions declined in the post-vaccine period when compared to the pre-vaccine period (notifications: IRR=0.07; 95% CI 0.04-0.13; hospitalisations: IRR=0.04; 95% CI 0.01-0.16). As did notification rates in Indigenous people aged 5-19 (IRR=0.08; 95% CI 0.05-0.13) and 20-49years (IRR=0.06; 95% CI 0.02-0.15) in targeted jurisdictions. For non-Indigenous people from targeted jurisdictions, notification rates decreased significantly in children aged <5years (IRR 0.47; 95% CI 0.31-0.71), and significantly more overall (IRR=0.43; 95% CI 0.39-0.47) compared to non-Indigenous people from non-targeted jurisdictions (IRR=0.60; 95% CI 0.56-0.64). The national hepatitis A immunisation program has had a significant impact in the targeted population with relatively modest vaccine coverage, with evidence suggestive of substantial herd protection effects.

Keywords: Epidemiology; Hepatitis A; Indigenous; Notification; Targeted; Vaccination.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adolescent
Adult
Aged
Aged, 80 and over
Australia / epidemiology
Child
Child, Preschool
Disease Transmission, Infectious / prevention & control*
Epidemiologic Studies
Female
Hepatitis A / epidemiology*
Hepatitis A / prevention & control*
Hepatitis A Vaccines / administration & dosage*
Humans
Immunization Programs*
Infant
Infant, Newborn
Male
Middle Aged
Population Groups
Prevalence
Young Adult

Substances

Hepatitis A Vaccines