A diagnostic once called a “genuine breakthrough” in COVID-19 testing by the chairman of the U.S. Senate Health Committee is facing a recall.

Ellume Health said it is recalling certain lots of its rapid at-home COVID-19 antigen tests because of an abnormal rate of false positives.  FDA said in a release that negative results do not appear to be affected by the manufacturing issue. The agency said that it was also working with Ellume to assess the company’s additional manufacturing checks and other corrective steps to help ensure that the issue is resolved.

About 427,000 tests kits, which were sent to retailers and the Department of Defense, were affected by the issue, according to a report from ABC News.

Sean Parsons, the company’s CEO said in a statement, “we understand that trust is central to fulfilling our purpose as a company, and we recognize that this incident may have shaken the confidence of some of those who trusted Ellume to help them manage their health and to take back a bit of control of their lives during this pandemic. To those individuals, I offer my sincere apologies – and the apologies of our entire company – for any stress or difficulties they may have experienced because of a false-positive result."

Ellume’s diagnostic was one of the first at-home tests given emergency use authorization by FDA. Ellume was granted right before the first COVID-19 vaccines secured EUA.

In data submitted to FDA from an independently run, simulated home-setting clinical study of 198 subjects ranging in age from 2 years to 82 years, the Ellume COVID-19 home test demonstrated 96% accuracy, with an overall sensitivity of 95% (positive percent agreement) and specificity of 97% (negative percent agreement) when compared to an emergency use-authorized RT-PCR laboratory test.

In individuals presenting with COVID-19 symptoms, the Ellume COVID-19 home test demonstrated a sensitivity of 96% and specificity of 100%, and in asymptomatic individuals, the test demonstrated a sensitivity of 91% and specificity of 96%.

The recall comes at a time when there is a huge surge in demand for COVID-19 diagnostics.

The Biden Administration has already announced it was investing an additional $1 billion to ensure tests are available to those who need them and to provide manufacturers with purchase commitments that allow them to ramp up their production.