(Reuters) – The rapid-growing Omicron variant has led to us becoming more dependent on quick at-home antigen testing to determine if we have COVID-19. Do we need to be wiping our noses, as well as our throats?

The guidance you receive depends on your current location.

Scientists believe that Omicron can be transmitted to people when the virus infects their saliva and throat but not before it reaches their noses. Therefore, it is important not to swab the nostrils too early.

This view was supported by a small U.S. study. The virus was detected in saliva samples from 29 Omicron-infected people three days prior to the results of antigen or lateral flow tests.

Rapid tests are generally less sensitive than lab-processed tests. This means they can produce more false positives. However, if your test is positive you will almost definitely have COVID-19. This makes antigen testing a very powerful tool to combat the pandemic.

Recent studies have shown that antigen testers in America should first clean their throats before cleaning the nose.

The U.S. Food and Drug Administration uses nasal samples for all antigen testing. It has raised concerns about the safety of home throat swabbing and advised that users follow the manufacturers’ directions.

Israel’s top official in health has stated that anyone self-testing COVID-19 should use rapid antigen tests.

Others, including the United Kingdom have authorized rapid antigen test that can either swab your throat or the entire nose.

The German minister of health stated that they would study the reliability of rapid antigen tests in the detection and publication Omicron variants.