Rapid Saliva-Based Test for COVID-19 Antibodies Could Scale Up Testing to Track Spread of SARS-CoV-2

A rapid point-of-care test under development could help improve understanding of the dynamic changes in the transmission of COVID-19 over time at population scale.

A team of scientists at the Johns Hopkins Bloomberg School of Public Health (Baltimore, MD, USA) is aiming to scale up rapid testing to track spread of the SARS-CoV-2 virus with their lab's saliva collection and antibody testing expertise. In addition to using saliva tests for hepatitis E, which in the US is commonly transmitted to humans from swine, their lab has also refined saliva tests to detect exposure to and infection with antimicrobial-resistant bacteria such as Staphylococcus aureus and influenza viruses. The researchers have also been investigating testing for antibodies for SARS-CoV-2, the virus that causes COVID-19, using a simple saliva test that is less invasive than standard blood tests. They have used the results to track the spread of the virus, including among people who never exhibited symptoms.

The researchers have been seeking opportunities to transition their lab's test, which has to be performed in a centralized lab, to a rapid testing point-of-care platform. Such a rapid test could help improve understanding of the dynamic changes in the transmission of COVID-19 over time at population scale. The rapid test's development will be accelerated thanks to a sponsored research agreement with GBS Inc. (New York, NY, USA), a life sciences company that is developing real-time point-of-care tests for COVID-19 and diabetes.

To scale up the saliva antibodies test, the team is seeking emergency use authorization for the technology from the US Food and Drug Administration, which allows unapproved medical products to be used to diagnose life-threatening diseases when there are no approved alternatives. Saliva samples can be collected at home or in remote locations. They can also be gathered more frequently and quickly, particularly among large or disproportionately impacted groups. The scaled-up antibody test results will also help researchers and decision-makers understand dynamic changes in COVID-19, including the pace of trajectories toward herd immunity versus immunity gaps. The latter could be used to help prioritize use of vaccines. In addition to the team's early SARS-CoV-2 antibody testing, the researchers have also added a saliva protocol to their research after early data showed saliva's equivalence to blood-based antibody tests and its diagnostic accuracy to identify COVID-19 cases.

"With each new pathogen we've taken on, this salivary antibody measurement approach has brought a new perspective about how to contribute to the scientific body of knowledge concerning exposure and infection," said Christopher Heaney, who heads the Environmental Health Microbiology and Immunology Laboratory.

"How can we bring rigor to community-based studies of infectious disease dynamics without creating a burden? That's where saliva comes in," added Heaney, an associate professor in the Department of Environmental Health and Engineering. "Everything about SARS-CoV-2's impact is uncovering structural inequities, where the barriers and lack of access to testing are most pronounced."


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Johns Hopkins Bloomberg School of Public Health
GBS Inc.