FLC | NCI joins federal effort to evaluate COVID-19 antibody tests

NCI joins federal effort to evaluate COVID-19 antibody tests

May 5, 2020

As part of a collaboration with the Food and Drug Administration (FDA) and several other government agencies and academic medical centers, NCI is evaluating commercially available antibody tests for SARS-CoV-2, the novel coronavirus that causes COVID-19.

NCI has already assessed several of the tests and has provided the findings to FDA.

While “cancer research and cancer care remain job number one at NCI,” said NCI Director Norman Sharpless, MD, “NCI has unique research capabilities and capacities. So, to help in this public health crisis, we believe, is a moral obligation.”

Because of its robust research infrastructure, including expertise in human papillomavirus (HPV) vaccines and an advanced serology laboratory, part of NCI’s Frederick National Laboratory for Cancer Research (FNLCR) has shifted its focus to provide independent testing and validation of SARS-CoV-2 antibody tests. Antibody tests, also called serology tests, can be used to identify whether individuals have antibodies against SARS-CoV-2 in their blood. Antibodies are proteins made by the immune system in response to an infection. If someone has antibodies to the virus, it means that the person is, or was, infected.

At the time of publication, FDA had authorized emergency use of 12 different antibody tests, but many more tests are available commercially that haven’t been reviewed by the agency. On May 4, the agency updated its earlier policy guidance on antibody tests for commercial test manufacturers related to emergency use authorizations and providing specific clinical performance expectations for these tests.

“Determining the next steps in our response to COVID-19 is partially dependent on an accurate assessment of our national efforts thus far, and the quality of data for making this decision is dependent on accurate testing products,” said FDA Commissioner Stephen Hahn, M.D., in a statement.

Validated serology tests are also crucial for further studies of COVID-19, including studies of disease prevalence (called seroprevalence), immunity, and candidate vaccines, explained Ligia Pinto, PhD, who is leading the antibody testing work.Pinto directs FNLCR’s Vaccine, Immunity, and Cancer Program and the HPV Serology Laboratory, which develops, optimizes, and validates serology tests for HPV.

Reviewing the accuracy of SARS-CoV-2 antibody tests is a collaborative effort between FDA, NCI, the Centers for Disease Control and Prevention (CDC), the National Institute of Allergy and Infectious Diseases (NIAID), the Biomedical Advanced Research and Development Authority (BARDA) in the Department of Health and Human Services, Mount Sinai Health System, and others.

NCI has an inherent interest in contributing to the COVID-19 response because people with cancer are more likely to get very sick and die from the disease, said Douglas Lowy, M.D., NCI’s principal deputy director and a leading expert on HPV. In addition, Sharpless noted, FNLCR has unique resources and capabilities that are tailor-made for public health emergencies like the current pandemic. And its scientists are no strangers to working on public health emergencies. Alongside experts from NIAID, they have helped respond to earlier virus epidemics, including SARS, Ebola, and Zika.

“A lot of the same principles apply when you go from one type of serology assay to another,” Pinto explained. “The work we have done with HPV serology has really prepared us to evaluate and validate technologies for the COVID-19 pandemic.”

The main goal of this effort is to determine whether available antibody tests are accurate. To answer that question, Pinto’s team runs each test on a validation panel of 110 blood samples. Thirty samples are from people who had a confirmed SARS-CoV-2 infection. Another 80 samples were taken from people before the COVID-19 pandemic started and, therefore, wouldn’t have been infected with SARS-CoV-2. Samples from the panel can be used to test for two types of antibodies: IgG and IgM.

To ensure accuracy, every sample in the validation panel was tested by at least two separate labs. Although the panel may not be representative of all sample types that may be encountered in a large population, it will help inform next steps in the pandemic response, Pinto said.

Results from NCI’s validation studies are being provided to FDA on a rolling basis; the agency will use the information to decide how the tests should be used and to inform additional regulatory decisions.

Another goal of this effort is to develop standards for SARS-CoV-2 serology tests, Pinto added. She and her team has experience there too: They are leading an initiative to standardize HPV serology tests used to monitor immune responses to HPV vaccines in patients participating in clinical trials.

And, as is the case for HPV, validated SARS-CoV-2 antibody tests are also needed for studies of potential COVID-19 vaccines. The tests are used to see if people who got the vaccine in clinical trials have protective antibodies in their blood and how long those antibodies remain active.