8 April 2020
Australian scientists are working on a test to determine whether a person is immune to the new coronavirus SARS-CoV-2, whether they are currently infectious and whether they are at risk of a severe form of the disease.
The scientists, led by Associate Professor Menno van Zelm from Monash University, together with Professor Robyn O’Hehir from Alfred Health, are repurposing technology they have recently developed to test for a patient’s immunity to allergens and influenza.
The researchers will be using cell samples from Melbourne and coronavirus hotspots Italy, China and New York. The test will look at memory B lymphocytes – a type of immune system cell that makes antibodies to fight infections caused by pathogens such as viruses. Memory B lymphocytes stay in the body after an infection and mobilise an immune response if the body encounters the pathogen again.
Memory B lymphocytes are some of the immune system cells involved in the protection elicited by vaccination.
If a person has a large population of memory B cells specific to a particular pathogen, then it is likely that the person has been infected in the past and will remain immune to the disease.
The team has already developed markers for the memory B cells formed after coronavirus infection and can measure the number of memory B cells in a patient, enabling an assessment of their immune status.
The test is also going to look for differences in the blood of patients with mild disease compared with that from people with severe infection, to search for biomarkers that can predict who might benefit from early medical intervention.
“It is important that we now move from needing a test that simply tells whether someone is infected – which is the priority now – to needing a test that can determine who is infectious, who is immune, who is going to get a serious case of the disease and who will only develop a mild case of upper airway infection,” team leader Associate Professor Menno van Zelm, said.
Other Australian researchers have already mapped the immune response to COVID-19 in a woman who recovered from the infection.