The Omicron era of the global Covid-19 pandemic is in full swing, prompting major changes in government responses to Covid-19 screening and public health measures worldwide. The emergence of the highly mutated, rapidly spreading Omicron variant has necessitated a change in strategy for Omicron screening for public health agencies in the wake of soaring Covid-19 case counts. Amongst an impressive array of diagnostic tests developed for detecting Covid-19, the world’s newest pandemic challenge is being met with one of the oldest tests available on the market – Thermo Fisher Scientifics’ TaqPath polymerase chain reaction (PCR) test.
While this year has seen the testing market increasingly shift to over-the-counter rapid antigen detection tests, Omicron’s underlying biology has put PCR tests such as TaqPath back in the spotlight. Thermo Fisher’s TaqPath test targets multiple regions of the viral genome and was singled out by the World Health Organisation (WHO) as the best-positioned diagnostic for screening potential cases of Omicron. Mutations in the gene encoding the viral spike protein render the TaqPath test less sensitive to PCR amplification. Because TaqPath redundantly targets two other viral genes in addition to spike, Omicron detection can be inferred by S-gene target failure (SGTF).
The WHO’s endorsement is set to boost sales of TaqPath and the Covid-19 PCR testing market in general, which is valued at $23bn worldwide. Weeks into Omicron’s arrival, the SGTF method for detecting the variant is putting Thermo Fisher at centre stage for coordinating global efforts in tracking Omicron. As the United Kingdom now stares down more than 90,000 Covid-19 infections daily, the UK Health Security Agency (UKHSA) is relying on TaqPath and SGTF to study the spread of Omicron – now being detected in more than 8,000 cases daily, according to the organisation’s daily report released on 19 December.
In Ontario, Canada’s most populated province, Public Health Ontario implemented universal screening for SGTF using TaqPath on 6 December. Ontario has now relied on TaqPath to screen all positive Covid-19 cases for SGTF, identifying more than 4,500 cases with SGTF. For its part, TaqPath has played an important role in providing real-world evidence for unravelling the mysteries surrounding Omicron. Public health data from Ontario’s screening efforts have revealed that Omicron’s rate of transmission (Rt) value has exceeded four – meaning that for each infected individual, four more people are expected to become infected. These developments have led Ontario’s science table to suggest that vaccinations – once seen as the silver bullet for bringing the pandemic to an end – will not be enough to curb the spread of Omicron. With lockdowns now coming back into effect in Europe, PCR testing and TaqPath tests will be instrumental in tracking Omicron as the world prepares to manage the latest wave of the pandemic.