Omicron testing: new covid guidelines, LFT results and everything else you need to know

With omicron infections surging around the world, many countries are changing their coronavirus testing guidelines to better deal with the new variant and the huge number of cases it is causing. Here’s what you need to know.


10 January 2022

A person drops solution onto a lateral flow test for covid-19

Lateral flow tests may be less likely to detect the omicron variant

George Clerk/Getty Images

Can you test positive without being infectious?

Even if you have had three doses of vaccine, a positive lateral flow test (LFT) result means you are infectious to others because it means virus protein is present in large quantities in your nose or throat. For that, the virus must be actively multiplying inside your cells.

However, PCR tests continue to give positive results for days to weeks after an infection, because they can detect tiny quantities of the virus’s …