High street retailer Superdrug has suspended sales of its antibody finger prick tests following warnings from a health regulator about the reliability of such tests.
The Medicines and Healthcare products Regulatory Agency (MHRA) on Wednesday called for a temporary halt to the tests, which look for evidence of infection two or more weeks previously, while “patient safety issues” are resolved.
The body said that people who have so far used a finger prick antibody test “should not consider the results to be reliable and should not take any action on it”.
Superdrug, one of the biggest providers of such tests, have suspended finger prick blood testing.
"We have voluntarily halted the Covid-19 antibody testing service while conversations with the MHRA are still ongoing," a statement read.
Superdrug became the first high street retailer to offer the service and numerous websites offer similar tests, including Lloyds Pharmacy.
Finger prick kits can sell from around £70.
The MHRA warning does not apply to antibody tests using blood obtained from the veins, which requires a healthcare professional to administer.
Two weeks ago The Telegraph revealed that Public Health England (PHE) had approved as effective the first of these tests, manufactured by Roche, and the Government has since ordered 10 million of them.
Because many of the finger prick antibody blood tests use the same technology in the laboratory as the Roche venous test, some online providers have wrongly claimed that their kits are “PHE validated”.
But PHE does not yet regard tests on blood samples taken from the capillaries on the end of the finger as effective.
Although it is too early to say for sure whether recovering from Covid-19 affords people immunity to future infection, many scientists expect that it will provide at least a few months’ protection.
A false positive result, therefore, could put people in danger by mistakenly letting them think they will not come down with the virus.
Graeme Tunbridge, Director of Devices at MHRA said:
“Patient safety and public health are our main priorities and it is in the interests of everyone for antibody tests to be as reliable and meaningful as they can be.
“There are several UK providers of testing services who offer Covid-19 antibody testing using a finger prick sample of capillary blood collected in a small container.
“We are asking all providers of laboratory-based Covid-19 antibody testing services using capillary blood collected by a finger prick to temporarily stop providing this service until home collection of this sample type has been properly validated for use with these laboratory tests.
“Use of unvalidated sample types may lead to unreliable results and as such we are working closely with the service providers, laboratories and test manufacturers to resolve the regulatory and patient safety issues.
“People who have purchased one of these sampling kits, and received an antibody test result, should not consider the result to be reliable and should not take any action on it.”