Singapore-made PCR kits able to detect both Omicron, Delta variants

Its two PCR test kits - Acu-Corona 2.0 and Acu-Corona Duplex - which can detect the Delta variant, can also identify the Omicron strain. These kits are already in use.

It was reported on Thursday (Dec 2) that two imported Covid-19 cases have preliminarily tested positive for the Omicron variant in Singapore.

The Acu-Corona 2.0 test targets two Covid-19 genes - RdRp and E - that are present in both the Omicron and Delta variants.

Meanwhile, the Acu-Corona Duplex test targets the E gene and S gene. The portion of the S gene targeted by the test does not contain any of the 32 mutations in the Omicron variant, hence it can detect the variant without any loss of sensitivity.

Omicron has a large number of gene mutations that have not been reported in a single viral variant before. So far, scientists have seen 32 mutations in the spike gene of Omicron, whereas there are nine mutations in Delta's spike gene, and this gives them reason to believe that Omicron may have fairly different characteristics from previous variants.

The spike protein is an important part of the virus that allows it to bind to human cells and facilitate infection of the cells. So a change in the spike protein may change the ability of the virus to infect cells and cause adverse effects.

Acumen Diagnostics said on Friday that since the kits are manufactured locally, they can be deployed quickly and cost about half the price of imported ones.

The firm currently operates two laboratories that can process 7,000 diagnostic tests daily.

Dr Ong Siew Hwa, Acumen Diagnostics' chief executive officer and chief scientist, said: "With PCR tests remaining the gold standard to detect Covid-19, Acumen Diagnostics remains well positioned to help Singapore tackle this new challenge posed by the virus."

Acumen Diagnostics is not the only firm whose existing kits are capable of detecting Omicron.

Biotech firm MiRXES, which is currently using its Fortitude 2.1 Covid-19 PCR kit in Singapore, has also said the kit can detect all Sars-CoV-2 variants of concern identified so far, including Delta and Omicron.

Local biotech company BioAcumen Global also said the new variant does not affect the detection capability of its existing kit, the BioA SARS-CoV-2 Real-Time RT-PCR kit v2.0. 

All these kits detect both Delta and Omicron, but are not able to distinguish between the two. To confirm if a positive Covid-19 case has been infected by the Omicron variant, gene sequencing is necessary.

A preliminary study by South African scientists published on Thursday suggests that the Omicron variant is three times more likely to cause reinfections compared with the Delta or Beta strain.

The spread of Omicron has upset the reopening of travel in many countries.

In Singapore, tighter border measures took effect from 11.59pm on Thursday, and three planned vaccinated travel lanes for Qatar, Saudi Arabia and the United Arab Emirates have been postponed indefinitely. 

Malaysia has temporarily banned the entry of travellers from countries that have reported the Omicron variant or are considered high-risk. The travel ban so far applies to eight African countries, including South Africa, Zimbabwe, Mozambique and Malawi, but this could be extended to other places where the variant has been detected.

By Clara Chong