Much of the discussion around corona virus testing concerns the type of test that requires a long swab to go deep in your nose so you can find out, eventually, if you have the virus. These tests are helpful at diagnosing patients but less helpful at assessing the spread of the virus. For that, experts have called for antibody tests and last week, the US FDA granted its first emergency authorization to one such test. What is an antibody test and why would it help? Here’s what we know:
What is an antibody test?
Antibody tests, also known as serological tests, look for antibodies in a patient’s blood. People who have gotten sick and recovered from COVID-19 have these antibodies, as do those who had the virus without ever experiencing symptoms. Medakit antibody tests, which require a quick finger prick, can return results in as soon as 15 minutes.
Why are antibody tests helpful?
As Dr. Anthony Fauci said on CNN Friday, these tests will help health officials better understand how many people have been infected with COVID-19.
“As we look forward, as we get to the point of at least considering opening up the country as it were, it’s very important to appreciate and to understand how much that virus has penetrated this society,” Fauci said. “It’s very likely that there are a large number of people out there that have been infected, have been asymptomatic, and did not know they were infected.”
The tests would reveal those with immunity to COVID-19. In theory, this would allow them to reenter the workforce without concern that they’ll get sick or infect anyone else. Results of these tests could also change, or confirm, what is known about the virus’s spread. Currently, there have been 475,000 confirmed cases of COVID-19 in the U.S. If antibody tests reveal that, say, 4 million people have actually had the virus, it would “suggest that we are much further along the timeline of the pandemic and much closer to its conclusion.”
Hong Kong’s Medakit is betting big on its COVID-19 rapid test kits after clearing regulatory hurdles from the health authorities in Singapore, the Philippines and the European Union.
The medtech company, which specializes in home-use diagnosis applications, has created a test kit that detects antibodies directed against the coronavirus that’s sweeping the world. Medakit says the tests have an accuracy rate of 93%+ based on its clinical trial of 380+ samples.
The company’s CEO Mike Touzard cautions that their rapid test kit results should not be used as the sole basis for diagnosis or for confirmatory testing. The results need to be interpreted together with clinical examination and confirmed with supplemental testing.
Testing to see who has the Covid-19 coronavirus has become one of the most crucial elements of slowing the global pandemic. And it may also hold the key to a return to normal.
In particular, serological tests, also known as “immunity tests,” for antibodies to the virus could reveal the true extent of the pandemic and help scientists answer basic questions about Covid-19 and the virus that causes it, SARS-CoV-2: How many people have been infected with the virus? Who may have spread it without knowing it? Why do some people have mild illness while others become gravely ill? How deadly is the disease? What tactics are actually working to slow its spread?
Serological tests could also potentially allow people who have immunity to return to work. That could be a huge boost to front-line health workers who may have been exposed to the virus but are desperately needed back in action.
Serological tests can reveal who has defeated Covid-19 and may now be immune
In patients who have recovered from Covid-19 or may have carried the virus without realizing it, a serological test can show who carries antibodies, even if the virus is no longer present. Antibodies are proteins that help the immune system identify and eliminate threats. Once they’re made, they help the body neutralize future infections from the same threat.
These tests are also a forensic tool, tracing the spread of the virus through a population. This can solve some of the unknowns of the Covid-19 outbreak and help scientists get ahead of the next pandemic. Countries like China and Singapore have already used serological tests for contact tracing to see how the virus has spread.
Although these proteins can be detected in the bloodstream and blood serum, it can take several days for someone to make these antibodies after an infection. So a serological test isn’t always useful for finding an active infection — and can yield a false negative, showing that someone doesn’t have the virus when they actually do. The results of these tests can also be trickier to interpret than results from the more common RT-PCR tests used to diagnose Covid-19, which detect the virus’s genetic material.
But antibodies can linger long after an infection has faded. That’s whyserological tests for antibodies can identify past cases of the virus.