Updated November 30th, 2021 at 14:46 IST

COVID-19: How to detect if you caught Omicron? Know if at-home molecular test effective

Widely prevalent RT-PCR tests search for specific identifiers [virus’ spike protein] in genetic material in the positive sample, scientists discuss if it works

Reported by: Zaini Majeed
IMAGE: AP | Image:self
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While the World Health Organisation (WHO) in its Monday briefing stressed that the global risk from the new highly mutated B.1.1.529 Omicron variant remains ‘high’, and the preliminary data suggests higher transmissibility, the global health agency ruled that it can still be easily ‘efficiently’ tested via a polymerase chain reaction [PCR] test. While many aspects about the virulence and strain’s impact are subject to research and further investigation from the sequenced samples and data submitted to the WHO through International Health Regulations (IHR), the organization outlined how the new COVID strain lineage can still be tested via the existing set ups in place in midst of the ambiguity about the symptoms when an individual likely contracts it.

Omicron variants can be detected by the RT-PCR tests, as compared to the previous variants that require genome sequencing. The widely prevalent RT-PCR tests search for specific identifiers [virus’ spike protein] in the genetic material in the positive sample and not the complete gene sequence. Because some of these identifiers in the Spike protein where Omicron is concerned will be ‘missing’ the variant can be immediately detected, hence controlling the spread at a relatively faster pace. RT-PCR diagnostics remain both ‘accurate and effective,’ scientists say, adding that the COVID-19 at-home molecular tests can also detect 100% of variant genome sequences of Omicron. 

Lucira's at home molecular tests can detect Omicron

United States based diagnostic company Lucira approved by the US FDA has confirmed that its COVID-19 Check-It (OTC) and All-In-One (Rx) molecular self-test kits has the “ability to detect 100% of Omicron variant genome sequences by targeting viral sequence regions unaffected by the spike protein mutations found in Omicron, Delta and other Variants of Concern, AP reported. Lucira’s tests can be conducted at home via the self-testing kits that the company claimed will deliver PCR results accurately and early detectability in a single-use, all-in-one kit with results in 30 minutes or less the infection with the new highly mutated Omicron.

Missing 'S factor' a test-maker

“As S gene target failure (SGTF) from a widely used PCR test is indicated for Omicron, the SGTF can be used as the marker for this variant, which may lead to efficient detection of Omicron,” said the WHO in its technical paper. 

WHO Health Emergencies Programme COVID-19 Technical Lead Dr. Maria Van Kerkhove told the press briefing that the early evidence on Omicron, known by the technical term B.1.1.529, shows that the variant has a large number of mutations, that affects its transmissibility, as also some of these mutations may have “concerning characteristics.” But Kerkhove did not rule out the early detection of the cases.

The missing S factor is a test maker that makes the COVID-19 diagnostics effective in detecting Omicron via normal RT-PCR testing. “COVID-19 testing kits provide accurate test results and are able to detect SARS-CoV-2 in samples containing the Omicron variant,” diagnostic specific medical facilities in the US have claimed. 

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Published November 30th, 2021 at 14:38 IST