SARS-CoV-2 serosurveys

 

NCIRS is co-leading the Australian COVID-19 Serosurveillance Network and a suite of serosurveys with the Kirby Institute to measure the prevalence of antibodies to SARS-CoV-2 in target populations. Serosurveys involve conducting serological tests on thousands of Australians across various age groups, geographical locations and target populations to determine whether someone has been exposed to SARS-CoV-2. The tests detect antibodies, which are made by the body following an infection with the virus. SARS-CoV-2 serosurveys provide critical information to estimate the spread of the 2019 novel coronavirus in the Australian community. Currently our understanding of the epidemiology of COVID-19 in Australia has been predominantly based on the identification of cases who have presented for testing because they are ill (have symptoms). While this allows us to see the “tip of the iceberg”, seroprevalance studies provide a broader view of previous SARS-CoV-2 infections, including mild and asymptomatic cases and those who may not have been tested during their infection. 

SARS-CoV-2 serosurveys are a key component of the Australian National Disease Surveillance Plan for COVID-19  and are listed as a precedent condition necessary to inform public health measures in the Australia’s Pandemic Health Intelligence Plan. Findings from these serosurveys are used to inform public health policy, vaccination strategies and mathematical models designed to predict future disease spread, associated morbidity and mortality, health service needs and the COVID-19 vaccination program.

  • 2022 serosurveys

    A new series of serosurveys is being conducted in 2022 among residual blood donor specimens in all states and territories. These surveys measure two kinds of antibodies: anti-nucleocapsid antibody, which indicates natural infection with SARS-CoV-2, and anti-spike antibody, which indicates either vaccination and/or natural infection. This work is funded by the Snow Medical Foundation and the Australian Government Department of Health.

    • The first collection was completed in early March 2022. The analysis found an overall anti-nucleocapsid (infection-related) seroprevalence of 17%, with substantial variation by jurisdiction, which reflects differences in epidemiology between states and territories. Prevalence was found to be highest in younger age groups. Anti-spike antibody prevalence was high across all age groups and jurisdictions, reflecting high vaccination coverage in Australia.
    • The second collection was completed in June 2022. The analysis found an overall anti-nucleocapsid (infection-related) seroprevalence of 46%, with less variation by jurisdiction compared with the first collection, which reflects the ongoing community transmission in all states and territories. The same age-related patterns were observed as from the first collection, with younger age groups having the highest seroprevalence, steadily decreasing with increasing age. Anti-spike antibody seroprevalence remained high across all jurisdictions and age groups, reflecting high vaccination coverage in Australia.
    • These surveys will be repeated every quarter in 2022, with the next beginning in late August, to track seroprevalence over time in relation to new COVID-19 waves and changes in pandemic restrictions.

     

    In addition to these blood donor surveys, a paediatric serosurvey began in July 2022. This is a repeat of the paediatric serosurvey completed in 2020–2021 and involves active collection of blood samples from children undergoing anaesthesia for elective procedures via the Paediatric Active Enhanced Disease Surveillance (PAEDS) hospitals network. This project is funded by the Snow Medical Foundation and the Australian Government Department of Health and Aged Care.

    The Australian COVID-19 Serosurveillance Network involves collaboration between public and private laboratories, Australian Red Cross Lifeblood, national and jurisdictional health department representatives and subject matter experts (refer to Major collaborators section). This network has been established to bring together collaborators and expertise, and facilitate the ability to draw on the same sites to repeat serosurveys at subsequent times.

  • 2020-2021 serosurveys

    Four serosurveys were completed over 2020–2021. These were led by NCIRS and the Kirby Institute, and involved many collaborators: 

    • The Sydney serosurvey, funded by NSW Health, with testing conducted at the Institute of Clinical Pathology and Medical Research (ICPMR), was undertaken from late April to early June 2020 in metropolitan Sydney using residual blood specimens from blood donors, pregnant women and people undergoing general pathology testing. The study found SARS-CoV-2 seroprevalence during the first COVID-19 epidemic wave in Sydney was below 1%, indicating that community transmission was low. See the full results of this serosurvey here
    • A national serosurvey was undertaken between June 2020 and August 2020 using residual blood specimens from blood donors, pregnant women and people undergoing general pathology testing in all states and territories. This project is funded by the Australian Partnership for Preparedness Research on Infectious Disease Emergencies Centre of Research Excellence (APPRISE CRE), the Snow Medical Foundation and the Australian Government Department of Health, and conducted in collaboration with various stakeholders in the Australian COVID-19 Serosurveillance Network. This study also found the seroprevalence to be below 1%, indicating that community transmission was low in all Australian states and territories. See the results of this serosurvey here.
    • A serosurvey in metropolitan Melbourne was conducted among residual blood donor specimens in November-December 2020. This project is funded by the Snow Medical Foundation and the Victorian Department of Health. See the results of this serosurvey here.
    • A paediatric serosurvey was conducted between November 2020 and March 2021. This involved active collection of blood samples from children undergoing anaesthesia for elective procedures via the PAEDS hospitals network. This project is funded by the Snow Medical Foundation and the Australian Government Department of Health. See the results of this serosurvey here.
  • Major collaborators

    Lead investigator team

    • NCIRS: Kaitlyn Vette, Noni Winkler, Associate Professor Heather Gidding, Dr Helen Quinn, Dr Alex Hendry, Lucy Armstrong, Dr Archana Koirala, Associate Professor Nicholas Wood, Dr Frank Beard, Professor Kristine Macartney
    • Kirby Institute: Dr Dorothy Machalek, Professor John Kaldor
    • The Royal Women’s Hospital: Hannah Shilling
    • Murdoch Children’s Research Institute: Professor John Carlin, Dr Marnie Downes
    • Australian Red Cross Lifeblood: Professor Iain Gosbell, Associate Professor David Irving, Dr Rena Hirani and team

     

    Laboratory methods leads

    • Victorian Infectious Diseases Reference Laboratory (VIDRL): Suellen Nicholson, Dr Theo Karapanagiotidis, Professor Deborah Williamson
    • Institute of Clinical Pathology and Medical Research (ICPMR): Dr Matthew O’Sullivan, Professor Dominic Dwyer

     

    Reference laboratories

    • VIDRL – Suellen Nicholson and team
    • ICPMR – Dr Matthew O’Sullivan, Prof Dominic Dwyer and team
    • Pathology Queensland – Robert Gibb and team
    • PathWest – Prof David Smith and team
    • SA Pathology – Dr Geoff Higgins and team

     

    Key collaborators and funding bodies

    • Public and private collection and testing laboratories
    • Jurisdictional health department representatives  
    • PAEDS sites
    • NSW Health
    • APPRISE CRE
    • Snow Medical Foundation Limited
    • Australian Government Department of Health
    • Victorian Department of Health

     

    We acknowledge and thank other collaborators involved, including those not specifically named above.

 
Read more about NCIRS serosurveillance work here