“How can we find out whether we are immune?
Serologic tests, or immunity tests, look for antibodies or proteins produced by humans’ immune system to attack pathogens in the blood. Running wide-scale testing would provide a more accurate picture of how many people have been infected and gained immunity to the virus, according to Peiris. This is important given that Peiris described the number of people who have been infected as an “iceberg”, and serologic tests would help to reveal some of the hidden cases.
“This iceberg, we don’t know how big this is,” he said. “The only way to find out the full size of the iceberg is to do serologic testing.”
Testing could also help in places like mainland China, where the focus has turned to gradually reopening businesses and schools. On Thursday, 91 new cases were reported on the mainland, of which 60 were asymptomatic.
If a large proportion of the population has been infected, then it should be safe to resume normal activities faster, Peiris said.
“But then you have to be much more careful, because the disease can come back and we know there are imported cases. So for these decisions to be made in the right way, antibody testing is extremely important.”