Many people who have fallen ill in recent months but have not been tested for COVID-19 have wondered if they have the coronavirus. Many others who did not get sick could also have been infected with the virus andPeople from both groups are now looking to for possible answers.
What are the antibodies? And how accurate are the tests?
Antibodies are proteins that the body makes to attack a virus. If someone has a certain antibody, it may mean that they have been infected in the past – whether they know it or not. Dr. Shoshana Ungerleider, an internal medicine physician at Sutter Health in San Francisco, told CBSN that having specific antibodies “means that you have been exposed to or have been vaccinated against this virus” .
However, according to Dr. David Agus, medical collaborator at CBS News, many antibody tests currently on the market are “advertising claims that make no sense”. He said that too little is known about the coronavirus to trust the results of most current antibody tests.
Tests with higher rates of false positive results could wrongly lead people to believe that they have antibodies when they really do not. False negatives can lead people to believe that they don’t have antibodies when they actually do.
“Aside from this latest FDA-approved antibody test that we hear about and which is very accurate, I should also point out that we don’t even know if most of the hundred or so other tests that are on the market are even close to be as specific, “said Underleider.
The FDA announced on Monday that it would start requiring companies testing anti-coronavirus antibodies to seek approval from the agency within 10 days of their release.
“Unfortunately, we see unscrupulous players marketing fraudulent test kits and using the pandemic as an opportunity to take advantage of American anxiety,” the FDA said in a statement.
Do Antibodies Mean You Are Immune?
While a test can accurately detect antibodies, Agus said that people who wear them cannot be assured that they are safe from the virus. Indeed, having the antibody does not necessarily mean that you are immune to the virus.
According to Agus, the body creates many antibodies to fight the infection, but not all of these antibodies will neutralize the virus – some just “hang on,” he said. “Until we have the immune component, for the individual person (an antibody test) does not make sense. “
Agus said cities and businesses could use an antibody test to see who has been exposed to the virus in the past, but could not know who is immune to it.
He said the next step is to pass existing tests and add an “immunity component” – but when it could be ready is unknown.
“There is no reason to take a test right now, unless you are part of an epidemiological study, [or] your company wants to know how many people have been potentially exposed. For reasons like that, they are important. But for personal decisions, right now, they shouldn’t be used, because they don’t tell you about immunity, “said Agus.Thursday.
White House Coronavirus Response Coordinator, Dr. Deborah Birxon April 19, having the virus and having immunity are two “different issues.” She said research is underway to determine if the antibodies provide protection.
“That’s why these ongoing plasma studies andto really see if this antibody gives protective immunity and help to the sick individual, as well as to really study with vaccines and see if the antibodies that are produced are working, “said Birx.
“These are questions that we still have scientifically. I’ll tell you, in most infectious diseases, except for HIV, we know that when you get sick and recover and develop antibodies, this antibody often confers immunity. I don’t know if it’s immunity for a month, immunity for six months, immunity for six years, “she said.
Dr. Ungerleider said “we shouldn’t be getting ahead of ourselves” with antibody testing. “I think the fact remains that we don’t yet know how long these antibodies last, the degree to which people with anti-coronavirus antibodies are actually protected from COVIDs a second or third time. “
“We must all remember that the new coronavirus is only 16 weeks old. So there are a lot of things we don’t know yet, ”she said.
Kate Gibson contributed to the report.