U.K. Regulator Urges Halt to Covid Finger-Prick Antibody Tests

(Bloomberg) -- Coronavirus antibody tests that use blood samples collected with a finger prick may be faulty, and patients shouldn’t rely on their results, U.K. health regulators said.

The Medicines and Healthcare Products Regulatory Agency is working closely with the providers, laboratories and manufacturers to resolve safety issues, Graeme Tunbridge, its director of devices, said in an emailed statement Wednesday.

Companies using blood collected by a finger prick should stop providing the service “until home collection of this sample type has been properly validated for use with these laboratory tests,” Tunbridge said.

Antibody tests that can detect prior exposure to coronavirus are considered key to determining how many people have been infected and may have immunity that would allow contact with others. While antibody tests are easier to scale up than molecular diagnostics, which look for the presence of active virus in body fluids, the field has been plagued with accuracy challenges.

“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,” Tunbridge said in the email.

The types of coronavirus tests targeted by the U.K. regulator are different from the kind developed by Roche Holding AG. The Swiss giant decided to use blood drawn intravenously, rather than from a simpler finger prick, because it’s more reliable, Chief Executive Officer Severin Schwan said last month. Testing failures might sow confusion among the public and politicians, he said then.

The U.K. has drawn criticism for its Covid-19 testing strategy, and the country has lagged behind European peers in using molecular tests to screen those who show symptoms. The government also previously bought antibody test kits that turned out to be faulty.

©2020 Bloomberg L.P.