Do lateral flow tests detect the Omicron variant? What we know so far

Scientists are still debating the efficacy of cheap antigen tests, but remain hopeful they work just as well

Scientists have warned of a rapid increase in Covid-19 cases attributed to the new omicron variant, though most people are presenting with only mild symptoms.

The World Health Organisation has warned that the variant carries a “very high” global risk of causing a surge in infections.

Crucially, experts have said it could take weeks to understand the severity of omicron, which was first identified in southern Africa, and what it will mean for the trajectory of the pandemic.

There remains some uncertainty over how effective vaccines and tests will be for the new variant.

As with much of the discussion around the new variant, the academic debate is still live and scientists are urging caution until more is known about it, however it is thought that lateral flow tests can pick up omicron infections.

Rupert Beale, who runs the Cell Biology of Infection lab at the Francis Crick Institute, wrote on Twitter that the picture was “complicated” and that while it was “possible that one or more of the commercial lateral flow devices might lose sensitivity”, early evidence suggested the many of the cheap and easy tests which have become a mainstay of the Covid testing regime would work.

He said “for now we can’t assume lateral flow tests are definitely OK for omicron”, but added that the “best guess is most of them will be”.

Dr Beale tweeted: “We cannot assume lateral flow tests maintain sensitivity against omicron – might depend on test, might also depend on intra-variant variation (and sure, they also could be all OK, we don't know).”

David LV Bauer, a virologist at the Francis Crick Institute, said a “large part of the uncertainty with LFTs [lateral flow tests] comes in because companies do not disclose exactly which part of the nucleocapsid protein they detect (i.e. the actual antigen)”.

Sandra Ciesek, a virologist at the Johann Wolfgang Goethe-Universität Frankfurt in Germany, wrote that she had conducted a trial that showed three lateral flow tests – produced by Roche, Siemens and Flowflex, which supplies tests to the NHS – were capable of detecting omicron.

QuantuMDx, a medical technology company based in Newcastle, said it had carried out analysis on its PCR tests, which showed they were able to detect omicron, but the company does not produce lateral flow tests and has therefore not looked at whether they work.

Peter Openshaw, professor of experimental medicine at Imperial College London, said on Saturday there were still “many crucial bits of information that we need to have: do lateral flow tests work? How severe is the disease it causes?”

However, the official advice remains to keep doing regular lateral flow Covid tests.

The advice in Scotland, for example, has been strengthened for the Christmas period, with people urged to take a lateral flow test “much more” often than the previous guidance of twice weekly.