FDA greenlights its first saliva-based COVID-19 antibody test

The FDA greenlighted its first antibody test that doesn’t use blood samples to check for evidence of a COVID-19 infection and instead relies on simple, painless mouth swabs.

Developed by Diabetomics, the rapid, lateral-flow diagnostic received an agency emergency authorization allowing it to be used at the point of care for adults and children. Designed to deliver a result within 15 minutes, the CovAb test also does not require any additional hardware or instruments.

When administered at least 15 days after the onset of symptoms, when the body’s antibody response reaches higher levels, the test demonstrated a false-negative rate of less than 3% and a false-positive rate of nearly 1%, according to the company. 

The diagnostic, which detects IgA, IgG and IgM antibodies, previously received a CE mark in Europe. In the U.S., the test is marketed by the company’s COVYDx subsidiary.

RELATED: NIH antibody study suggests COVID-19 spread across U.S. earlier than originally known

Diabetomics pivoted its efforts toward the COVID-19 pandemic after working to develop a saliva-based test for estimating weekly glucose levels in people with Type 2 diabetes. It is also working on a blood-based test for the early detection of Type 1 diabetes in children and adults; both have yet to be FDA-approved.

The company previously launched a point-of-care test for detecting preeclampsia during the first trimester of pregnancy. The potentially dangerous complication is associated with high blood pressure and organ damage but may show few other symptoms.

RELATED: NIH antibody study uncovers millions of hidden, uncounted COVID-19 cases

Recently, antibody tests have begun to paint a clearer picture of the earliest months of the COVID-19 pandemic, providing evidence that the coronavirus reached U.S. shores long before it was considered a national emergency, and that millions to tens of millions of potentially asymptomatic cases went undetected.

This research, performed by the National Institutes of Health, relied on archived and dried blood spot samples collected from tens of thousands of participants. 

One study, using specimens originally collected during the first months of 2020 for the NIH’s All of Us population research program, found COVID antibodies that pointed toward active infections across the U.S. as early as December 2019, if not before. Those findings build on reports from the American Red Cross, which found antibodies in blood donations given around that time.

A separate study, which recruited more than 240,000 participants, found the official case count as of last summer could be off by nearly 20 million. Researchers estimated that for every COVID infection that was confirmed, nearly 5 slipped by undiagnosed, based on the number of people testing positive for antibodies