AMSTERDAM - Dutch public health institute RIVM has carried out experiments with coronavirus self testing kits and did not find a difference in the ability to detect Delta and Omicron variants of the virus, broadcaster NOS said on Wednesday.

The RIVM was commenting on a report by the FDA in the US, which said that home antigen tests may be less sensitive to detecting the Omicron variant.

The FDA said in a statement that antigen tests ‘do detect the Omicron variant, but may have reduced sensitivity,’ which means the tests could miss an infection, particularly in the early stages of the disease.

‘The RIVM has researched the self tests which are for sale in the Netherlands using the live Omicron virus grown in a lab,’ virologist Chantal Reusken told NOS. The FDA research involved the living virus in samples from patients.

Reusken said there are two reasons why a test could be less effective at detecting the Omicron variant. ‘The virus could have mutated so much that the tests don’t work as well, but we don’t expect that to happen,’ she said. ‘The protein spike in Omicron has changed but the antigen test is not focused on the protein spike but on the virus shell, which has hardly changed.’

It could also be that the Omicron variant is less easy to detect in the nose, she said. The FDA is now looking into this option.

The Dutch health ministry changed its protocol for self tests at the start of this month, and urged people with mild symptoms to use them. People with a positive result, or whose symptoms remain for a few days, should take a PCR test, the health ministry says.

Last week, 47,000 people who had a positive self test at home reported to their local health board testing center to double check, and 16% were found not to have coronavirus after all.