Six months into the pandemic and when economies open, antibody tests are popping up everywhere – although medical experts warn that they still don’t know for sure whether the COVID-19 antibody offers any protection.

They do not know how strong the antibody is, if it offers any immunity or how long it will stay in your system.

Adding to the uncertainty is the flood of tests on the market – more than 200 – whose results vary widely.

Nevertheless, medical facilities in Michigan offer antibody testing to learn how widespread COVID-1

9 is in communities. The tests will also help researchers better understand how it spreads and identify individuals who may be immune or eligible to donate plasma to infected COVID-19 patients in life-threatening situations.

Medical researchers are eager to learn if the COVID-19 antibody is like SARS and MERS antibodies, which last for about two years, or, if it acts as the measles antibody, that offers a lifetime of immunity. The latter is the hope for medical experts, though they stress that it will take many months, maybe years, for antibody testing and patient monitoring to figure it out.

“There is some reason to think that people (with the antibody) are safe … there is a lot of anecdotal evidence to say that people are probably safe – but we don’t know for sure,” Dr. Matthew Sims, director of infectious disease research at Beaumont Health, which offers antibody testing to the public and its 38,000 employees.

According to Sims, Beaumont’s antibody test involves a blood draw, which he said is more reliable than the finger prick test. That method is similar to a pregnancy test and offers only a yes or no answer, he said, while the blood draw provides more detailed information, such as the number of antibodies a person has.

“We’re still learning about the antibody test,” Sims said, emphasizing: “With COVID-19, we don’t expect it to disappear. There will be out there … and we have much more to learn about this virus than we wish. ”

related: Beaumont says it is launching the country’s largest study on COVID-19 antibodies: What it means

Where can you get the antibody test?

All Beaumont Urgent Care centers across metro Detroit currently offer COVID-19 antibody testing. You don’t need a recipe. There is no copy. And you can book time online or go inside.

The test involves a blood draw and the results usually come back in a few days, sometimes the same day. Beaumont tests about 3,000 people a day with Abbott’s IgG antibody test, which has FDA approval for emergency use. Abbott says its IgG test is very accurate, with a specificity of 99.6% and a sensitivity of 100%, although other studies have found slightly lower numbers.

Coronavirus antibody tests usually look at two antibodies produced in an infected person: IgM, which is one of the first types of antibodies produced after infection and is most useful in determining recent infection. Then there is IgG antibody, which generally develops after IgM and can remain detectable for months or years.

Henry Ford Health Systems, which has established its own antibody test, plans to announce its guidelines and plans to administer its test on Friday. According to Dr. Richard Zarbo, president of pathology and laboratory medicine at the Detroit-based hospital system, Henry Ford has a “validated test” with “greater than 99% sensitivity and 99.8% specificity to minimize false positive results.”

Wayne State Physicians Group, ACCESS (an Arab American community nonprofit) and Ford have also partnered to offer antibody testing using a mobile device. The group drives to sites that request testing for employees or members, perform blood draws and may have results back in a few days. Municipalities, companies and groups can request a visit from the team.

In western Michigan, Spectrum Health of Grand Rapids also offers COVID-19 antibody testing to the public. An order from a doctor is required. Spectrum has the capacity to perform up to 1,000 antibody tests per day, with results usually available within 24 hours. The cost of the test is $ 45 and should be covered by most insurance plans.

“We know that everyone who gets a positive result on this test has been exposed to COVID-19,” said Susan Smith, senior director of laboratory services at Spectrum Health. “We hope this testing will help us learn more about how the disease is spreading in our community and who it has affected.”

Negative results are not always right

According to the CDC, COVID-19 antibodies usually become detectable 1-3 weeks after the onset of symptoms, “when evidence indicates that the contagion is likely to have greatly decreased and that a certain degree of immunity to future infection has been developed.”

However, there are questions about the accuracy of antibody tests that have flooded the market over the past three months. Of the 200 plus antibody tests introduced so far, fewer than 20 have received FDA approval for emergency purposes.

The quality of a coronavirus antibody test is measured in two ways. Sensitivity is the test’s ability to detect antibodies to the disease. An error in sensitivity can give false negative, indicating the absence of these antibodies when they actually exist.

Specificity represents the test’s ability to identify individuals who were not infected with coronavirus and did not produce antibodies to the disease. An error in specificity can produce a false positive, indicating the presence of antibodies that are not there.

According to Dr. Mary Schmidt, an expert on infectious diseases and associate professor of clinical medicine at Virginia Commonwealth University, tends to make coronavirus patients with severe illness make higher antibodies.

In comparison, with a mild form of the disease, they tend to produce fewer antibodies, or none at all, potentially triggering a negative antibody test result. The immunocompromised, such as cancer patients undergoing chemo, transplant patients and people on prednisone, also tend to make fewer antibodies, Schmidt said.

“There are other people who just don’t have good immune systems. Some people just don’t have the ability to make good antibodies,” Schmidt said, noting antibody testing is a science that has been around for at least three decades.

“We have several types of ways to control for these antibodies, and we are only learning now by controlling more and more people, which are the most sensitive … which of these tests brings up the real positives,” said Schmitt, chair of the Schmidt & Libby Health Advisory Group,

Scmidt recommends that people get antibody tests that require a doctor’s order and / or be created by a university, and warned that the quick well tests that use a drop of blood are “more complicated” than their blood-drawing counterparts and “do not pick up antibodies.”

“It’s a big competition. Medical technology has distinguished itself so quickly,” Schmitt said. “You have all these companies with the capacity to roll out these products. They come every week, and you can’t just say we have enough, because you might be missing a really good one.”

Schmidt said the coming months will tell when researchers are monitoring those who had positive antibody tests. This is the validation phase, where antibody tests will be tested.

“They will be validated with real patients,” Schmidt said. “It’s exciting to see this happen. You have to realize that most of these tests – they’ve been created since January.”

She stressed: “That’s so much of what we don’t know.”

The FDA is squeezing down

When the pandemic first hit, the FDA, eagerly fighting the deadly virus, allowed companies to validate and sell their own antibody tests: They had to state a disclaimer that the FDA had not approved its product.

But then came a tsunami of tests. More than 200 hit the market, with many companies making false claims about the tests and their accuracy, says the FDA, which chased down.

In early May, the FDA issued a new policy requiring test manufacturers to apply for emergency use approval within ten days of a test being validated. To date, fewer than 20 antibody tests have been approved by the FDA for emergency use, although about 200 tests remain on the market, sparking controversy on Capitol Hill this week.

At a congressional hearing Tuesday, FDA’s former lead scientist Jesse Goodman accused the FDA of causing “chaos” by allowing companies to self-validate and flood the market with unreliable tests. He was among several experts urging the FDA to speed up the review of about 200 antibody tests that are still on the market and get rid of “junk tests.”

Among the most important critics was the US rope. Raja Krishnamoorthi, D-Illinois, who blasted the FDA over its initial flaccid handling of antibody tests.

“The FDA took business after its word. When I ask my children to clean their room, I can tell my wife and I do not trust self-validation. But this is the policy that the FDA adopted until recently, “Krishnamoorthi said at the hearing.

At the same time, the CDC urges the public and physicians to concentrate their attention on the antibody tests that have been approved for urgent use by the FDA.

But until tests have been validated, and more about actual immunity is known, the CDC warns against citizens and employers who put too much stock in the tests.

“Additional data is needed before recommending public health recommendations based on serological test results, including decisions to discontinue physical distance and use personal protective equipment,” says CDC.

The CDC also warns that positive antibody tests should not be used to make the following decisions:

  • There should be no change in clinical practice or the use of PPE by healthcare professionals and first responders who test positive for COVID-19 antibody.
  • Positive antibody results should not be used to make decisions about grouping people, for example in schools, dormitories or prisons.
  • Antibody test results should not be used to make decisions about returning people to the workplace.

As the CDC states in its guidance on COVID-19 antibody testing:

“We do not currently have enough information to say if anyone will definitely be immune and protected from re-infection if they have antibodies to the virus … these tests are not 100% accurate and some false positive or false negative results may occur. . “

Contact Tresa Baldas: [email protected]

COVID-19 antibody tests approved by the FDA include:

  • Cellex Inc. – qSARS-CoV-2 IgG / IgM Rapid TestOrtho Clinical Diagnostics, Inc.
  • VITROS Immunodiagnostic Products Anti-SARS-CoV-2 Total Reagent Pack
  • Chembio Diagnostic System, Inc. – DPP COVID-19 IgM / IgG System
  • Mount Sinai Laboratory – COVID-19 ELISA IgG Antibody Test Serology IgG
  • Autobio Diagnostics Co. Ltd. – Anti-SARS-CoV-2 fast test
  • Ortho-Clinical Diagnostics, Inc. – VITROS Immunodiagnostic Products Anti-SARS-CoV-2 IgG Reagent Pack
  • DiaSorin Inc. – LIAISON SARS-CoV-2 S1 / S2 IgG
  • Abbott Laboratories Inc. – SARS-CoV-2 IgG Assay
  • Bio-Rad Laboratories, Inc. – Platelia SARS-CoV-2 Total Ab Analysis
  • Wadsworth Center, New York State Department of Health – New York SARS-CoV Microsphere Immunoassay for Antibody Detection
  • Roche Diagnostics – Elecsys Anti-SARS-CoV-2

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