SARS-CoV-2 testing was an integral part of many people’s lives in Singapore. With access to anti-COVID pills from primary-care settings on the horizon, the eye-watering, sinus-stinging experience of an Antigen Rapid Test (ART) swab looked set to stay on beyond the need for routine testing.
To spare everyone’s sniffers, a team of scientists from Duke-NUS, its academic medical partner SingHealth and the National University of Singapore developed a saliva-based SARS-CoV-2 ART that showed promise in early clinical testing, nearly matching the sensitivity to the gold standard Polymerase Chain Reaction (PCR) test.
Dubbed the Parallel Amplified Saliva Rapid Point-of-Care Test, or PASPORT, the technology leverages a proprietary on-kit amplification technique, developed by Duke-NUS alumnus Dr Danny Tng, to produce results from a saliva sample in minutes.
Like other ARTs, PASPORT uses nanoparticles to bind the virus. But it is also coated with a second type of nanoparticles. These bind to the first set to amplify the signal. Because of its two-stage amplification, PASPORT can detect the virus at much lower viral loads, making it more sensitive at flagging SARS-CoV-2.
This also means that it can be used any time of the day, even after eating or drinking. The results of a clinical study involving more than 100 participants, which were published in Microchimica Acta on 6 December 2021, showed that PASPORT’s sensitivity in detecting the virus was 97 per cent and its specificity, 90.6 per cent.
“A reliable and painless saliva antigen test that is affordable and convenient to perform would encourage more [people] to be tested, and more frequent testing,” said lead inventor Tng, a medical officer with the Department of Infectious Diseases at SGH, and adjunct research fellow with Duke-NUS’ Emerging Infectious Diseases Programme in a media release issued today.
Tng, who graduated from Duke-NUS in 2019, added, “This may enable us to manage COVID-19 more effectively not only at the point of care, but also in settings such as airports, conventions and even at home.”
Requiring only saliva pooled in the mouth, the test is simple and easy to use.
“With this, we hope that more people will do the test as a personal act of social responsibility before engaging, especially, in large-scale events or gatherings,” said Professor Soo Khee Chee, a senior co-inventor of the test, who is Benjamin Sheares Professor in Academic Medicine with the SingHealth Duke-NUS Oncology Academic Clinical Programme.
Duke-NUS and SingHealth filed intellectual property protection for the invention and entered into a licence agreement with Digital Life Line, a Singapore-based company. The inventors hoped that through close collaboration with commercial partners, the product could be out in the market as soon as possible as countries around the world moved to making treatments available faster and in primary healthcare settings.
“[Oral antiviral drugs] will need to be given as early as possible after illness onset for maximal benefit,” said Professor Ooi Eng Eong from the Emerging Infectious Diseases Programme during a press briefing today.
“A test that can be self-administered or used on-site in the primary care setting may mitigate the need for cases to be managed at the hospitals.”