The National Institutes of Health is planning to test for antibodies against the coronavirus in samples taken from 10,000 of the newest participants to join in its broad-based research effort known as the All of Us program.
With Quest Diagnostics as a partner, the agency Tuesday said it will start testing blood samples taken in March and work back in time until no samples test positive for antibodies against SARS-CoV-2.
Through the tests, NIH aims to show the prevalence of exposure to the COVID-19 virus in the study population and inform assessments of the proportion of people previously infected in different regions.
The U.S., like many countries, was unable to test everyone with COVID-19-like symptoms for genetic material indicating an active infection during the early months of the outbreak. That fact, coupled to uncertainties about the prevalence of asymptomatic carriers, means it is unclear how many people have already been exposed to the virus and may therefore have some immunity against it.
Antibody testing enables researchers to look back and better understand when the virus became established in a region and how widely it spread. NIH is using its existing 350,000-subject All of Us research program to generate those insights.
The COVID-19 portion of the program will test samples from the 10,000 or more people who most recently signed up to participate. Working with healthcare provider partners, NIH has already taken blood samples from the participants, giving it the means to see when people developed antibodies against the coronavirus. The most recent samples were taken in March. In-person sample collection is currently on pause.
NIH is yet to disclose which antibody test it will use in the study, saying only that the assay has FDA emergency use authorization and is designed to detect IgG antibodies.
Some of the tests that Quest has used as part of its antibody testing services — including ones from Ortho Clinical Diagnostics, Abbott and PerkinElmer's Euroimmun — have all had their accuracy evaluated with help from NIH's National Cancer Institute.
The accuracy of antibody testing has been a subject of debate in recent months, albeit more in the context of using the results to determine the immunity of individuals than in research studies. NIH has acknowledged the potential for false positives, stating it may perform follow-up tests on positive samples to determine if the antibodies are specific to SARS-CoV-2. Antibodies generated in response to other coronaviruses could trigger positive results on SARS-CoV-2 serologic assays.
NIH will conduct the antibody tests as part of a broader COVID-19 study. The study will also involve collecting survey data on how COVID-19 is affecting the physical and mental health of participants, and analyzing electronic health records to learn more about symptoms associated with infection.
Separately, NIH on Monday said it launched a "centralized, secure enclave" to keep medical record data from individuals in the U.S. diagnosed with COVID-19. The goal is to allow scientists to analyze the data to better understand the disease and develop treatments.