Serology point-of-care tests are not the same as rapid antigen point-of-care tests.
COVID-19 serology point-of-care tests can detect human antibodies produced in the days or weeks after a person is infected with the SARS-CoV-2 virus or received a vaccination.
Like pregnancy tests, they usually come in a small plastic cassette. However, COVID-19 serology point-of-care tests require blood.
Some states and territories have prohibited or restricted the use of serology point-of-care tests. Visit the relevant government website for more information.
We have approved several COVID-19 serology point-of-care tests with restrictions.
This includes restrictions on who can use them.
Important messages
- COVID-19 serology point-of-care tests cannot determine whether a person is infectious.
- COVID-19 serology point-of-care tests are not able to detect if a person has been recently infected.
- Management of an effective COVID-19 response relies on accurate reporting of COVID-19 infections from all facilities that offer testing.
- It is illegal to supply or advertise these COVID-19 serology point-of-care tests as self-tests or home use tests in Australia.
Offering point-of-care serology services
COVID-19 serology point-of-care tests cannot be advertised to consumers. There are also obligations for any advertisements directed to health professionals.
A significant risk in serology point-of-care testing relates to misinterpretation of the result.
Accurate identification of a COVID-19 infection based on serology results requires an understanding of how the antibody response develops with time, and how there is a significant lag time between infection and the development of antibodies.
In Australia, all point-of-care serology tests detect IgM and/or IgG antibodies that develop after SARS-CoV-2 infection.
These tests do not detect the SARS-CoV-2 virus itself.
These tests can detect if a person has been exposed to the SARS-CoV-2 virus. They can't tell if someone is infected or had a recent infection.
Positive serology point-of-care result
A positive IgM, IgG and/or IgA serology result indicates that a person has been exposed to the SARS-CoV-2 virus.
They might have a COVID-19 infection and are potentially infectious.
A positive result may be enough to assume COVID-19 infection in a symptomatic person, but it should be confirmed by a lab test.
You should follow current Communicable Diseases Network Australia guidelines.
Negative serology point-of-care result
It can take up to two weeks, or even longer, for a serology point-of-care test to detect antibodies that are produced in response to a viral infection or following vaccination.
It is recommended that COVID-19 serology point-of-care tests should not be used until at least two weeks post onset of symptoms.
A negative IgM, IgG and/or IgA serology result cannot rule out a current COVID-19 infection. This is particularly true if a patient has no symptoms or has had symptoms for less than two weeks.
The ability of serology tests to accurately detect exposure to the SARS-CoV-2 relies on their sensitivity and specificity, which can vary significantly between different assays. Serology tests can be cross-reactive and detect antibodies produced in other infections. For example, less severe seasonal coronaviruses circulating in the community can induce antibodies that cross-react in a COVID-19 test to produce false-positive results. Serology tests can also fail to detect COVID-19 if testing is performed in the acute phase of the infection prior to the development of detectable antibodies.
Serology testing is generally used in epidemics to aid in the investigation of the outbreak to better understand the rate and pattern of infection.
It relies on public health reporting networks to capture serology point-of-care test results.
Serology testing may also be useful if SARS-CoV-2 nucleic acid tests are repeatedly negative, but the patient's symptoms and epidemiology are strongly suggestive of infection with COVID-19.
Further investigation should be done by a specialist in infectious diseases.
Testing to confirm immunity status
We have not approved any serology point-of-care tests that can definitively provide information on an individual's immune status against COVID-19.
It's not proven that serological tests are an effective way to test for COVID-19 immunity.
The existing scientific evidence does not support the claim that a positive antibody test indicates an individual is immune to SARS-CoV-2.
Absence of antibodies following vaccination does not necessarily mean that the person will not mount a response to a SARS-CoV-2 infection in the future, nor does the presence of antibodies guarantee that the patient will be protected from symptomatic disease, or onward transmission of the virus.
Multiple agencies in Australia and overseas agree with this position.
Currently, the Public Health Laboratory Network (PHLN) does not recommend routine diagnostic serological tests pre- or post-vaccination except in specific cases where this kind of testing may be requested as part of the assessment by a treating medical practitioner to inform a patient's clinical pathway. For example, immunocompromised patients.
Point-of-care testing considerations
There are several issues that need consideration for any point-of-care testing services.
These include:
- potential for misidentification of the patient and/or test specimen
- infection risk for the patient and the operator.
Blood specimens collected for point-of-care testing, as for other forms of testing, should be regarded as potentially infectious not just for SARS-CoV-2, but also for other blood-borne infectious diseases.
Staff must be trained in appropriate specimen collection and infection control.
To offer COVID-19 serology point-of-care testing, your staff should:
- have the knowledge, experience and capabilities to safely and accurately carry out the specimen collection and testing,
- correctly interpret the results and
- be able to provide current and correct health advice based on these results.
The National Pathology Accreditation Advisory Council has published guidance on key considerations for COVID-19 point-of-care testing used in health care settings.