The test can give results inside 15 minutes—yet it’s not exactly as precise as different tests.
For quite a long time, the US has had issues with coronavirus testing—predominantly a deficiency in that department, which has, to some degree, repressed authorities’ endeavors at containing the pandemic. Be that as it may, on May 9, the US Food and Drug Administration made a stride towards making testing all the more generally accessible by giving a crisis endorsement for an antigen test to help recognize those with COVID-19, as indicated by an announcement discharged by the office.
The fast test—formally known as the Sofia 2 SARS Antigen FIA, made by the Quidel Corporation in San Diego—vows to “quickly detect fragments of proteins found on or within the virus by testing samples collected from the nasal cavity using swabs,” as indicated by the FDA. This most up to date COVID-19 test is like quick strep or influenza tests, and can give results inside 15 minutes, as indicated by Quidel’s site.
Be that as it may, how does this more up to date, snappier test contrast with different tests at present accessible in the battle against the COVID-19 pandemic? This is what you have to know.
What precisely is an antigen test, and how can it work?
To comprehend antigen testing, you need to realize what an antigen is. “An antigen is a substance recognized by the body’s immune system, which can [then] respond by generating proteins called antibodies that specifically recognize that antigen,” Albert Shaw, MD, a Yale Medicine irresistible ailment specialist and teacher of medication at Yale School of Medicine, discloses to Health.
That signifies, “the point of an antigen test is to detect the presence of a protein—the nucleocapsid protein—which is part of the SARS-CoV-2 virus that is the cause of COVID-19,” says Dr. Shaw. In that sense, and per FDA’s announcement, an antigen test fundamentally searches for those sections of antigens inside an individual’s body to check whether they’re contaminated with the infection.
As per the FDA, antigen tests are gathered by means of nasal cavity swabs, “which [are] then placed into a special solution for virus detection,” says Dr. Shaw. The principle favorable position of antigen tests, per the FDA, is the speed at which they can give results (once more, Quidel’s site says their antigen test can show results inside 15 minutes). Notwithstanding speedy outcomes, antigen tests are additionally less expensive and simpler to utilize, contrasted with different tests accessible. Once “multiple manufacturers enter the market,” the FDA brings up that it “can potentially scale to test millions of Americans per day.”
How are antigen tests not the same as immunizer and PCR tests?
The FDA clarified that through the span of the COVID-19 pandemic, it has been giving crisis use approval (EUA) for two distinct sorts of testing techniques: polymerase chain response (PCR) tests and serological (or counter acting agent) tests.
PCR tests, per the FDA, recognize the hereditary material from the infection—or the infection’s RNA—which can help analyze a functioning COVID-19 contamination. That is not the same as antigen tests, which, once more, test for the infection’s proteins. “Up until now, the tests used to detect [active infections of] the virus detect the genetic material of the virus, not proteins,” Ellen Foxman, MD, PhDa, Yale Medicine research center medication specialist in the Clinical Virology Lab at Yale Medicine and an associate teacher of lab medication, tells Health. These PCR tests, nonetheless, are as yet done through nasal or throat swabs.
Counter acting agent tests, then again, search for antibodies an individual’s resistant framework has made in light of the infection—that assists specialists with deciding if an individual has recently been presented to COVID-19. (Starting at the present moment, while authorities assume that the nearness of antibodies implies an individual will have some resistance to COVID-19, it’s muddled how much, or to what extent it endures). Those counter acting agent tests are additionally done through testing an individual’s blood serum or plasma. While antibodies and antigens are both regularly proteins, “a positive antigen test reflects active infection, while a positive antibody test reflects recent or past infection,” says Dr. Shaw.
Are there any drawbacks to antigen tests?
While antigen tests are eminently speedier than PCR tests, the drawback to sped up might be diminished exactness: The FDA says antigen tests aren’t as explicit at PCR tests, and may give bogus negatives—which at that point should be affirmed through a PCR test. Fortunately, per the FDA, “positive results from antigen tests are highly accurate.”
“We expect antigen tests to be less sensitive than PCR tests because the PCR tests have an amplification step that makes them able to detect very tiny quantities of viral genetic material,” Dr. Shaw explains.” Dr. Someone speculate this affectability of this new test will be most elevated in early COVID-19 ailment in patients with significant levels of infection, yet the “false-negative” rate, particularly in later illness, will be essential to know.” Dr. Foxman includes that this kind of test regularly has an affectability of around 80-85%, “which means it is expected to miss 15-20% of infections.”
Antigen tests additionally aren’t intended for home use and requires a specific instrument to be run in guaranteed labs, says Dr. Shaw, which implies they may even now not be as promptly accessible as everyone trust immediately. Yet, by and large, any expansion in testing is valuable in the battle against COVID-19. “Antigen tests will play a critical role in the fight against COVID-19 and we will continue to offer support and expertise to help with the development of accurate tests, and to review and monitor marketed tests to ensure accuracy, while balancing the urgent need for these critical diagnostics,” said the FDA.
The data in this story is precise as of press time. In any case, as the circumstance encompassing COVID-19 keeps on advancing, it’s conceivable that a few information have changed since distribution. While Health is attempting to stay up with the latest as could reasonably be expected, everyone likewise urge perusers to remain educated on news and suggestions for their own networks by utilizing the CDC, WHO, and their nearby general wellbeing division as assets.