A new COVID-19 test that can rapidly assess if a person has been previously infected with the coronavirus is now available to hospitals in Singapore.
Launched on Friday (May 15), the cPass serology test detects antibodies – formed by the body to fight off infections – in the blood or serum of patients.
It is not used to check for active infection. Its main purpose rather, is for contact tracing, detecting asymptomatic cases and assessing herd immunity. Such serological tests have been used in Singapore for contact tracing.
What is different about the new test developed by Singapore’s Duke-NUS Medical School is that it produces results in just an hour instead of days, a world first.
The test looks for the presence of neutralising antibodies, which are those that can block the SARS-CoV-2 virus that causes COVID-19.
In other words, an indicator of immunity against the virus.
“In most cases, neutralising antibodies equal protection or (is the) best indicator of protection,” said Professor Wong Linfa, director of the Duke-NUS’ Emerging Infectious Diseases programme and the principal investigator for the test.
“The cPass developed by our team can be used for contact tracing, reservoir or intermediate animal tracking, assessment of herd immunity, longevity of protective immunity and efficacy of different vaccine candidates.”
Aside from a rapid turnaround, other advantages the cPass serology test has are safety and scalability.
Current tests for neutralising antibodies require live virus and cell materials, which are processed by highly skilled operators in biocontainment facilities. Using protein engineering, the new test replicates a part of the virus and a part of a live cell that binds to each other.
“Basically, what is happening in your body, we have mimicked in a test tube with two engineered proteins,” said Prof Wong.
This means that the test has the potential to be mass produced and can be used to test a large number of people more quickly, and can be conducted in most labs without potentially exposing lab operators to live viruses, experts told the media at a press conference on Friday.
Professor Wang said that it took his team less than two months from conception to product development, to provisional authorisation of the test kit by Singapore’s Health Sciences Authority, which was granted last week.
Biotech firm GenScript did the proof of concept research, product design and development, and is now commercialising the test. The Diagnostics Development Hub (DxD) at Singapore’s Agency for Science, Technology and Research (A*STAR) validated the test kit and developed the manufacturing protocol and quality controls for it.
DxD Hub will also produce the pilot batch for use in Singapore hospitals.
“This innovative cPass diagnostic kit will be instrumental in supporting the fight against the global pandemic,” said Dr Sidney Yee, CEO of DxD Hub. “We are making cPass available to hospitals as we speak.”
Prof Wong added that there was keen interest from around the world and within the region. The test is already being tried in Malaysia and Thailand.
Dr Zhu Li, chief strategy officer of GenScript, said that applications for approval for the test are already being filed in Europe and the United States, while the company has set up production capability in China and in US in anticipation of demand.
“The test results will be of great help to governments in guiding the resumption of work since it is extremely useful for quick and reliable surveillance to determine how widely a population has gained immunity to SARS-CoV-2 virus,” he said.
“Detection of neutralising antibodies determines who can more safely go back to work or to more social life.”
This has important implications for countries that are formulating their exit strategies from lockdowns, said Professor Wong, adding that the test can also help to assess blood samples for plasma therapy.
Blood plasma from recovered COVID-19 patients can be used for treatment if they have high levels of neutralising antibodies and the test can help to measure this quickly, said the professor.
“This could be a game changer in the field of COVID-19 investigation,” said Professor Patrick Casey, senior vice-dean of research at Duke-NUS.