Regulators are providing standardized human plasma panels for the detection of the disease.
Food and Drug Administration officials announced it will provide pharmaceutical drug researchers with panels of human plasma samples to support the regulatory evaluation of serological tests used to detect recent Zika virus outbreaks.
The two primary blood diagnostic tests for the detection of Zika are nucleic acid tests and serological tests. Nucleic acid tests identify infection by confirming the presence of a virus’ genetic material, while serological tests detect antibodies (proteins) produced by the immune system. Serological tests are particularly crucial said the FDA, because often there is just a short time available when the virus’ genetic material is detectable.
FDA Commissioner Scott Gottlieb explained that: “At the onset of the Zika virus outbreak, when little was known about the disease or how to diagnose it, the FDA worked quickly with manufacturers to encourage the development of diagnostic tests and ensure they were available using its Emergency Use Authorization authorities,” he continued. “By providing manufacturers of these tests with standardized patient samples to use in properly validating these diagnostics, we will be able to better assess how well their tests perform. This is part of our effort to ultimately bring these tests through the FDA’s formal review process to better ensure their reliability, and to enable broader access to Zika diagnostic testing.”
Federal regulators noted that the development of serological tests is very challenging because antibodies produced to fight Zika are tough to differentiate from antibodies the immune system produces to fight related viruses, including West Nile and dengue viruses. The panels, said FDA, consist of samples from anonymous donors infected with one of those three viruses. Although the panels are not used for research, diagnostic developers can be used to distinguish between West Nile, Zika and dengue viruses. “Using the same serological panel to evaluate different devices available under Emergency Use Authorization (EUA) will help public health professionals compare the performance of different Zika virus tests,” noted the FDA.
According to the announcement, the panels were prepared with samples from Zika virus-infected patients provided by Blood Systems Research Institute (BSRI) via a study supported by the National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH).