The US Food and Drug Administration (FDA) has issued warning letters to three companies for marketing adulterated and misbranded Covid-19 antibody tests.

Warning letters were issued to Medakit Ltd. of Sheung Wan, Hong Kong; Antibodiescheck.com and Yama Group; and Dr. Jason Korkus, DDS and Sonrisa Family Dental d/b/a My COVID19 Club of Chicago, Illinois.

Violations outlined in the warning letters include offering test kits for sale in the US for at-home use without marketing approval, clearance or authorisation from the FDA; labelling that falsely claims the products are FDA-approved; and labelling that bears the FDA logo, which is not permitted for use on private sector materials of any kind.

At present, there is no diagnostic or antibody Covid-19 test authorised by the FDA to be used completely at home.