What is serosurveillance?

Serosurveillance provides estimates of antibody levels against infectious diseases and is considered the gold standard for measuring population immunity due to past infection or vaccination. It is an important component of disease surveillance and complements notification, hospitalisation, mortality and immunisation coverage data. National serosurveillance programs are well established in many countries worldwide.

Serosurveillance for SARS-CoV-2 infection

NCIRS is co-leading the Australian COVID-19 Serosurveillance Network and a suite of serosurveys with the Kirby Institute to measure the prevalence of SARS-CoV-2-specific antibodies in target populations. 

Four SARS-CoV-2 serosurveys, led by NCIRS and the Kirby Institute and involving many collaborators, were completed across 2020–2021. A new series of serosurveys among the Australian blood donor population is being conducted in 2022.

Funding for this work has been provided by the Australian Partnership for Preparedness Research on Infectious Disease Emergencies (APPRISE) Centre of Research Excellence, Snow Medical Foundation, Australian Government Department of Health and the Victorian Department of Health and Human Services. 

Visit NCIRS Serosurveillance for SARS-COV-2 page to access results of the past surveys and learn more about serosurveys currently underway.

 

Serosurveillance for Japanese encephalitis virus infection

NCIRS is leading the national human Japanese encephalitis virus (JEV) serosurveillance program, funded by the Australian Government Department of Health and Aged Care.

Japanese encephalitis virus infection primarily causes asymptomatic illness, but around 1 in every 250 human infections results in encephalitis or other serious neurological outcomes. Therefore, many more people are likely to be infected than detected via reporting of cases with symptoms. The seroprevalence studies will provide information on the extent of the spread of JEV in the community to inform targeted public health interventions.

NCIRS is working with state and territory governments, the Australian Red Cross Lifeblood, and public health laboratories to conduct seroprevalence studies among populations considered at-risk for JEV infection. Active consent-based surveys using blood collected directly from participants and surveys using residual sera are underway in several jurisdictions.
 

Vaccine preventable disease serosurveillance 

NCIRS, in collaboration with the Centre for Infectious Diseases and Microbiology Laboratory Services (CIDMLS), at Pathology West – ICPMR, Westmead, commenced a national serosurveillance program in 1996, and has been conducting national serosurveys at approximately 5 yearly intervals. Each serosurvey involves collecting a bank of 7,000–13,000 plasma or serum specimens from diagnostic laboratories throughout Australia that receive samples from hospitalised and ambulant people. The specimens are collected opportunistically from residual/leftover specimens submitted for testing that would otherwise have been discarded and are randomly selected to represent the Australian population.

The collection and storage of specimens is managed by CIDMLS, as is the testing for immunity to the VPDs of interest using disease-specific in-house or commercial serological assays. NCIRS is responsible for the direction of the national program and the subsequent data analysis and interpretation of the serological results. Ethical approval is obtained for each serosurvey. 

Serosurvey 1 (1996–1999): measured population immunity to measles, mumps, rubella, varicella, hepatitis A, hepatitis B, hepatitis C, diphtheria, tetanus, polio and pertussis.

Serosurvey 2 (2002): measured population immunity to measles, rubella, varicella, hepatitis B, pertussis, meningococcal C, cytomegalovirus and Helicobacter pylori.

Serosurvey 3 (2007): measured population immunity to measles, mumps, rubella, varicella, pertussis, meningococcal C, diphtheria, tetanus and hepatitis B.

Serosurvey 4 (2012–2013): measured population immunity to measles, mumps, rubella, human papillomavirus and polio.

Serosurvey 5 (2018–2019): specimens collected and stored but not yet analysed.

In light of the COVID-19 serosurveillance experience, consideration is currently being given to the optimal model for an ongoing national vaccine preventable disease serosurveillance program.

A full list of publications from our serosurveillance program is available here.

Potential applications of our serosurveillance program
  • Examining trends of immunity over time 
  • Evaluating the impact of vaccination programs
  • Identifying groups at risk
  • Informing immunisation policy
  • Disease modelling
  • Estimating the burden of specific VPDs
  • Predicting potential outbreaks
  • Contributing to verifying disease elimination
  • Identifying infection with new or emerging pathogens and assisting with public health responses
Acknowledgements

We wish to thank the staff of all the laboratories that have contributed sera/plasma to our national serosurvey program for their valuable contribution.

Last updated August 2022