• On Thursday, the US Food and Drug Administration announced that more than two dozen antibody tests sold to Americans have not been proven to work
• A Mayo Clinic experiment found that half of the ninee antibody tests it analyzed were unreliable
• Antibody tests detect immune proteins developed in response to an infection and may provide some protection against reinfection
• The tests flooded the market with little review as officials looked to the results of antibody as a possible indicator of when the US could safely reopen
• Here’s how to help people impacted by Covid-19

By ASSOCIATED PRESS and NATALIE RAHHAL ACTING US HEALTH EDITOR

PUBLISHED: 17:40 EDT, 21 May 2020 | UPDATED: 19:13 EDT, 21 May 2020

US regulators said 27 vendors can no longer sell their coronavirus antibody test as part of the Food and Drug Administration’s (FDA) crackdown on scores of blood tests that have not yet been shown to work.

The FDA on Thursday published a list of more than two dozen test makers that have failed to file applications to remain on the market or already pulled their products.

The agency said in a statement that it expects the tests ‘will not be marketed or distributed.’ It was unclear if any of the companies would face additional penalties.

Most companies faced a deadline earlier this week to file paperwork demonstrating their tests’ performance.

Regulators required it after previously allowing tests to launch with minimal oversight, which critics said had created a ‘Wild West’ of unregulated testing.

It comes amid growing skepticism about the accuracy of antibody testing. The Mayo Clinic and ABC News found that half of the nine antibody tests they put through the paces were unreliable – including one that said a drop of saline had coronavirus.

The FDA website shows more than 175 tests have either filed applications with the agency or are in the process of doing so. A dozen companies have already been reviewed and authorized by the FDA to sell the tests after meeting requirements for accuracy and reliability.

‘We have seen a high level of collaboration and engagement from developers who want to get this right,’ said FDA Commissioner Stephen Hahn in a statement.

Antibody tests are different from the nasal swab tests currently used to diagnose active infections.

Instead, the tests look for blood proteins called antibodies, which the body produces days or weeks after fighting an infection. Most use a finger-prick of blood on a test strip.

An antibody test might show if you had COVID-19 in the recent past, which most experts think gives people some protection.

But studies are still underway to determine what antibody level would be needed for immunity.

It’s also not yet known how long any immunity might last or whether people with antibodies can still spread the virus.

For now, antibody tests are most useful for researchers trying to track how the virus spreads in communities.

Under pressure to increase testing options, the FDA in March essentially allowed companies to begin selling antibody tests as long as they notified the agency of their plans and provided disclaimers, including that they were not FDA-approved.

The FDA is now working with the National Institutes of Health and other federal health agencies to vet the accuracy of the tests, and determine how they can be used to track and contain the virus.

The more specific an antibody test is, the less likely it is to incorrectly identify antibodies developed to fight a different infection instead of those developed in response to SARS-CoV-2, the virus that causes COVID-19.

Sensitivity is a measure of how likely a test is to pick up antibodies when they’re present.

The push for the tests to be available meant that many labs rushed theirs to market before they’d tested them on enough people to have sufficient data to deem them reliable.

As the FDA continues to review data submitted by test makers, more serologic tests are likely to be added to the agency’s list of sub-par products.

ANTIBODY TESTS THAT CAN NO LONGER BE SOLD IN THE US
Artron BioResearch Inc./ Artron Laboratories Inc. COVID-19 IgM/IgG Antibody Test*

BestNovo (Jiangsu) Medical Technology Co., Ltd. BestNovo COVID-19 IgM/IgG Antibody Rapid Test Kit

Biobase Biodustry (Shandong) Co., Ltd. SARS-CoV-2 IgM/IgG Antibody Test Kit (Colloidal Gold)

BioMedomics, Inc. COVID-19 IgM-IgG rapid test*

Bioscience(Chongqing) Diagnostic Technology Co., Ltd. Qualitative Diagnostic Kit for Novel Coronavirus (2019-nCoV) IgM Antibody

Bioscience(Chongqing) Diagnostic Technology Co., Ltd. Qualitative Diagnostic Kit for Novel Coronavirus (2019-nCoV) IgG Antibody

Bioscience(Tianjin) Diagnostic Technology Co., Ltd. Qualitative Diagnostic Kit for Novel Coronavirus(2019-nCoV) IgM Antibody

Bioscience(Tianjin) Diagnostic Technology Co., Ltd. Qualitative Diagnostic Kit for Novel Coronavirus(2019-nCoV) IgG Antibody

Boson Biotech Ltd. Co (Distributed by Pure Genetic Medical Ltd.) Rapid 2019-nCoV IgG/IgM Combo Test Card

Changchun Wancheng Bio-Electron Co., Ltd. COVID-19 IgG/IgM ANTIBODY RAPID TEST KIT (Colloidal gold immunochromatography)

Diazyme Laboratories, Inc. Diazyme SARS-CoV-2 Antibody Rapid Test*

Genlantis Diagnostics, Inc. CovidQuik Coronavirus (COVID-19) IgM/IgG Antibody Test*

Hangzhou Clongene Biotech Co., Ltd. COMBRA COVID-19 IgM/IgG Rapid Test Cassette

Hangzhou Testsea Biotechnology Co., Ltd. One Step SARS-CoV2(COVID-19) IgG/IgM Test*

Hunan RunKun Pharmaceutical Co., Ltd. SARS-CoV-2 lgM/lgG Test Kit (Colloidal Gold)*

IMMY, Inc. clarus SARS-CoV-2 Total Antibody EIA*

Jiangsu Eubo Biotechnology Co., Ltd. EUBO COVID-19 IgG/IgM Rapid Test Cassette (WB/S/P)

Lifeassay Test-it COVID-19 IgM/IgG Lateral Flow Assay

Phamatech COVID19 IgG / IgM Rapid Test*

Promedical COVID-19 Rapid Test

Saladax Biomedical COVID-19 IgG/IgM Rapid Antibody Test*

Shanghai Eugene Biotech Co., Ltd. SARS-CoV2 (COVID-19) IgG/IgM Rapid Test

Shenzen Landwind Medical Co., Ltd. COVID-19 IgG/IgM Rapid Test*

VITA Testing COVID-19 IgM/IgG Antibody Rapid Test Kit

Zhengzhou Fortune Bioscience Co., Ltd. COVID-19 Antibody Rapid Test Kit (Colloidal Gold Immunochromatography Method)

Zhengzhou Fortune Bioscience Co., Ltd. COVID-19 IgM Antibody Rapid Test Kit

Zhengzhou Fortune Bioscience Co., Ltd. COVID-19 IgG Antibody Rapid Test Kit

Zhongshan Bio-Tech Co Ltd. SARS-CoV-2 IgM/IgG (GICA)*