National Serosurveillance Programme

Background
A National Serosurveillance Programme for Ireland, including a Seroepidemiology Unit (SEU), is being established in the HSE Health Protection Surveillance Centre (HPSC). Serosurveillance is a type of surveillance that measures the level of antibodies to a disease in the blood of a representative sample of the population, providing important information on population immunity due to past infection or vaccination. It is an important component of disease surveillance, and, as such, is a core function of HPSC. The programme will provide timely serosurveillance information on COVID-19 and other infectious diseases of public health concern.

The proposal for establishing this programme followed a report on the results of the first national population seroprevalence study for COVID-19 (SCOPI) published in August 2020. The logistical challenges in undertaking this work highlighted the importance of having a properly resourced and dedicated unit exclusively carrying out critical seroprevalence studies as part of its core function.

Aims and objectives of National Serosurveillance Programme
The aim of the national serosurveillance programme is to measure community-based cumulative population seroprevalence of COVID-19 and other infectious diseases of public health concern by age, sex and geographic area over time using residual serum or plasma specimens from different sources. Residual serum or plasma specimens are blood samples that have undergone all requested laboratory tests and are due to be discarded. Depending on the testing algorithms chosen, it will be possible to distinguish between naturally-acquired and vaccine-derived seroprevalence of COVID-19.

This surveillance system will be in a position to provide information on the spread of infectious diseases of public health importance in the population, and inform planning of vaccination programmes and other preventive activities.

Programme Components
The National Serosurveillance programme comprises three components:

  1. A seroepidemiology unit (SEU) at the Health Protection Surveillance Centre (HPSC)
  2. A seroprevalence function at the National Virus Reference Laboratory (NVRL), and
  3. A network of participating biochemistry laboratories.

1. Seroepidemiology Unit (SEU)
The SEU will comprise a dedicated multi-disciplinary team. It is the coordinating centre with overall responsibility for the functioning of serosurveillance activities in Ireland. Its functions will include the design of the serosurveillance sampling strategy, oversight of sample collection, statistical analysis and communication of results, and establishment of national and international connections with other serosurveillance programmes.

2. National Virus Reference Laboratory (NVRL)
NVRL is Ireland’s national virology reference centre. Established in the early 1960s to carry out poliovirus surveillance, following the introduction of the polio vaccine into Ireland, surveillance has been a core function of the NVRL since its inception. Building on that history, its functions in relation to seroprevalence will include determining the most appropriate laboratory testing methodologies to be used for serology, providing or obtaining access to those methodologies, analysing serum/plasma samples submitted by referring laboratories for antibodies to SARS-CoV-2 and, in time, other infectious diseases, and interpreting and advising on the test results.

3. Partner laboratories in each Hospital Group
Partner laboratories will participate by providing residual biochemistry samples (leftover, due for discard) for measuring population seroprevalence. This will involve identifying samples in accordance with the sampling requirements of the SEU, retrieving the samples, taking an aliquot (small portion), and packaging and arranging for transport of the aliquot specimens to NVRL.

Data Processing
All specimens sent to NVRL for testing are completely anonymised before leaving the participating laboratories. No personally identifiable information is shared with NVRL, and no personally identifiable information is collected or stored by the HPSC SEU. Further information on data processing can be found here

Outputs
The SEU will produce regular reports for dissemination of findings on seroprevalence of SARS-CoV-2 and, in time, other infectious diseases of public health concern, by age group, sex and geographic region. Information will be available to the public as well as to policy makers (Department of Health and HSE). All reports will contain aggregated data only; it will not be possible to identify any individual from these reports.

In addition, an interactive dashboard will be made available on the HPSC website. This dashboard will allow users to interactively select results across multiple parameters. Examples of similar dashboards can be found on the WHO endorsed SeroTracker website, supported by the Public Health Agency of Canada. All information displayed on the dashboard will be aggregated data only; it will not be possible to identify any individual through the dashboard.

Further information
Please direct any queries to the National Serosurveillance Programme at: seu.programme@hpsc.ie 

Last updated: 18th October 2021