ID NOW identifies whether an individual has been exposed to the coronavirus and developed an immune response to it, which experts say helps understanding immunity and potentially lift restrictions.
The product has been authorised in the US for emergency use and is not approved otherwise.
However, the US Food and Drug Administration warned on Thursday that Abbott’s kit may deliver inaccurate results, after receiving 15 reports of false negatives.
The agency, which is investigating the matter, said it can be used but negative results need to be double-checked with other tests.
Abbott pointed out that some studies have employed ID NOW “in ways that it was not designed to be used” and said it is clarifying the product information to provide better guidance.
“Negative results should be presumed negative, but if inconsistent with clinical signs and symptoms or necessary for patient management, should be tested with an alternative molecular assay,” the company said.
On Thursday, UK authorities said they were in talks with Swiss pharma giant Roche to buy its Covid-19 antibody tests after Public Health England said it is effective.
Shares in Abbott dropped 3% to US$89.18 in premarket trading.