Coronavirus SARS-CoV-2 inSIGHT™ T Cell Immunity

The Coronavirus (COVID-19) SARS-CoV-2 inSIGHT™ T Cell Immunity test measures the strength of T cell responses to SARS-CoV-2 specific antigens (Spike and/or Nucleocapsid protein). The test evaluates and reports the activity of CD4 and CD8 T cell responses independently.

About Coronavirus SARS-CoV-2
Please refer to the CDC website for the most up to date information on SARS-CoV-2 or COVID-19 at
https://www.cdc.gov/coronavirus/2019-ncov/summary.html.

At the end of 2019, an outbreak of the virus initially referred to as 2019 novel Coronavirus, later identified as SARS-CoV-2, occurred in Wuhan, Hubei Province, China. A betacoronavirus, like MERS-CoV and SARS-CoV, the virus originates from bats. As of January 30, 2020, the International Health Regulations Emergency Committee of the World Health Organization declared a “public health emergency of international concern.”

The disease caused by SARS-CoV-2 has been named coronavirus disease 2019, abbreviated as COVID-19. Main symptoms of the disease include fever, cough and shortness of breath. The CDC recommends reaching out to a physician if you develop symptoms and have been in close contact with a person known to have COVID-19; or if you have recently traveled from an area with widespread or ongoing community spread of COVID-19. The virus is spread via person-to-person contact through respiratory droplets produced when a person coughs or sneezes. The best preventative measures are to avoid close contact with people who are sick; avoid touching nose, eyes and mouth; cover a cough or sneeze with a tissue and discard immediately; and clean and disinfect frequently touched objects and surfaces using a household cleaning spray or wipe. Washing your hands with soap and water for at least 20 seconds frequently is one of the best preventative measures and hand sanitizer can be used when soap and water are not available.

About SARS-CoV-2 Antigens and Proteins
SARS-CoV-2’s single-stranded RNA genome encodes for a number of different proteins including spike (S), envelope (E), membrane (M), and nucleocapsid (N). The coronavirus is named for the notable spike glycoproteins evident on the viral envelope, (coronam is latin for crown). The spike glycoprotein is composed of two subunits, S1 and S2. The S1 domain contains the receptor binding region of the viral spike protein that mediates binding of the viral particle to the surface protein on the host cells. The S2 subunit specifically is highly conserved which is why it is a primary target for most vaccine development. The nucleocapsid (N) protein is an RNA-binding protein that the virus needs for replication and transcription. The N protein is also conserved and has shown to both produce an immune response and due to ample expression, is detectable during infection.

About SARS-CoV-2 Cell Mediated Immunity
The immune status of individuals who have recovered from SARS-CoV-2 has been found to be highly variable depending on the intensity of the infection, the treatments received while infected and the length of time since recovering from the infection. Additionally, the immune response developed by study participants in vaccine trials is also variable and wanes over time.

Whole blood is stimulated with SEB, SARS-CoV-2 Spike (S) and/or Nucleocapsid (N) proteins, or left unstimulated as a negative control and incubated at 37ºC. During the incubation Brefeldin A is added, causing the cytokines (interferon (IFN)-gamma, IL-2 and tumor necrosing factor (TNF)- alpha) to be retained inside the cell. Following the stimulation phase, cells are recovered, stained for cellular markers (CD3, CD4, CD8, CD69) and the cytokines above, and analyzed by flow cytometry. This test was developed and its performance characteristics determined by Eurofins Viracor. This test has not been cleared or approved for diagnostic use by the U.S. Food and Drug Administration.

Test will measure single and polyfunctional cytokine responses to both spike and nucleocapsid peptides.