ConsumerLab.com Answers  

COVID-19 Virus and Antibody Tests Compared and Where to Get Them

Reviewed and edited by Tod Cooperman, M.D. Tod Cooperman, M.D.
Initial Posting: 5/9/2020    Last Update: 8/8/2020

Question:
How can I get tested for the coronavirus? Can I get a home-test for COVID-19? Which are the best tests? Are any tests free?
Coronavirus (COVID-19) Tests: How and Where to Get -- COVID-19 Test Tube and Swab
Answer:
These are great questions, as many people want to know if they are currently infected or have already been infected with coronavirus that causes COVID-19 and have developed antibodies due to immune response. There has been much confusion and about tests for coronavirus and the FDA has reported that some test developers have falsely claimed their tests are FDA approved or authorized and that many commercial tests are performing poorly, so it is important to sort out the facts.

Before we get into specifics, let's start with a quick overview of the types of tests for coronavirus.

Types of COVID-19 Tests

There are basically two types of tests for the coronavirus that causes COVID-19:

Virus test
This test detects the virus (SARS-CoV-2) to determine if you have an active infection and are infectious, i.e., you can spread the virus. Although you can be infectious before showing any symptoms, the virus is best detected during the first week of symptoms (which is about two weeks after becoming infected from exposure) (Sethuraman, JAMA 2020).

The virus test is best done by collecting a sample of mucous from a swab (typically from the nasopharynx or nostril) or saliva. There are two type of virus tests: the PCR and antigen test. Both tests need to be analyzed in a laboratory or with a special rapid, portable machine.

The PCR test uses a technique that amplifies genetic material (RNA) from the virus. This can take as little as a few minutes or several hours. The FDA has begun allowing some at-home sampling kits to be sold by which you can collect your own sample and drop it off or mail it to a lab, which will report the results back to you.

The other type of virus test is the antigen test. It identifies a protein (or "antigen") that is specifically found on the virus. Advantages of the antigen test are that it can provide results in just 15 minutes and can be produced at lower cost, lending itself to wider use in screening. In addition, only a nasal swab is needed from the nostrils, not a much deeper, nasopharyngeal swab. The downside with antigen tests is that they are more likely to provide a false negative result than a gene amplification test; that is, it's more likely to identify your sample as negative when you are actually positive. Consequently, negative results from an antigen test may need to be confirmed with a gene amplification test — but a positive result is considered accurate. So far, the FDA has authorized only two antigen tests, the Sofia 2 SARS Antigen FIA from Quidel Corporation and the BD Veritor System for Rapid Detection of SARS-CoV-2. There appears to be a significant difference in the accuracy of these two tests. [Sign in for our comparison of the accuracy of the Sofia (Quidel) and BD antigen tests, which differ.]

Antibody test
This test detects antibodies to the virus and requires blood — either a drop or a vial — to determine if you have been infected in the past and have developed some level of immunity. This test (also called a serology test) can be run in a laboratory or on a test strip, although even test strips must be used in an authorized facility, not at home. As it takes time to develop antibodies that can be detected, antibody tests are most accurate when performed at least 20 days after the first disease symptoms. Tests focus on levels of the antibody IgG, which persists without much decline for several weeks, but may include levels of IgM which fall off more rapidly (Sethuraman, JAMA 2020). These tests look for antibodies to specific parts of the virus, namely its spike proteins (proteins on the outside of the virus that can bind to receptors on human cells) or nucleocapsid proteins (proteins inside the virus). An advantage to testing for antibodies to the nucleocapsid is that these antibodies can be easier to detect, however, antibodies to the spike proteins are believed to be more important in conferring immunity against the virus, as these antibodies may block viral entry into cells — although antibodies to nucleocapsid proteins may still serve as proxies for immunity. See Finding the Best COVID-19 Test to learn which marketed tests target each protein. [Note: Avoid taking large doses -- 10,000 mcg or more -- of biotin (a B vitamin) for several days before an antibody test, as biotin may skew results.]

Another way our bodies fight the virus is with T cells. Preliminary research suggests that even if antibody levels are too low to be detected, people previously infected with the virus may produce enough T cell response to provide immunity (Sekine, MediRxiv 2020). However, currently authorized tests do not measure this type of immunity, and one should still apply distancing and health precautions regardless of test results.

Some labs may provide you with an index value that reflects the strength of the antibody signal produced from your test. Higher antibody levels generate higher signals and higher index values. The interpretation of these index values depends on the test used. For example, for a particular test the cut-offs could be "less than 1.01" for negative, "1.01 to less than 1.21" for indeterminate, and "greater than or equal to 1.21" for positive (Theel, J Clin Microbio 2020). Or, there could just be a single cut-off index value of, say, 1.40 for positive, with anything below being negative (Example: Abbott Alinity -- https://www.fda.gov/media/137910/download). If you would like to know your index value, be sure to check that the lab you use provides the value.

Who is checking these tests?
To speed the availability of tests, rather than put these through its normal approval process, the FDA has provided a special emergency use allowance (EUA) for tests that, although imperfect, may be useful at this time. So there are actually no FDA "approved" SARS-CoV-2 virus tests, but a list of "FDA authorized" tests. The FDA allowances are based on data submitted by the test manufacturers, but the National Institutes of Health (NIH) and other government laboratories are now conducting independent tests of these tests and the FDA has been making the results public (see results in the Finding the Best COVID-19 Test section and watch for further announcements in our newsletter.)

Several other organizations around the world have been testing the test and/or certifying virus and antibody tests. The European Union's has been certifying tests, conferring on them its CE (Conformité Européenne) mark, and the Chinese National Medical Products Administration (NMPA) has been doing the same. Researchers in California, Denmark, and elsewhere have been testing the antibody tests. 

Be aware that in June 2020 the FDA warned consumers about at-home antibody tests being sold without FDA clearance or approval and issued warning letters to three companies selling these tests. Some of these tests were falsely labeled as FDA approved.

Where to Get COVID-19 Tests

Virus Test
To date, the FDA has permitted the use of over 90 virus tests. The vast majority must be performed on a sample collected in a medical setting, such as in a doctor's office, a diagnostic laboratory, or a drive-through facility, but the FDA has also begun authorizing at-home sample collection tests for the virus.  

Local testing (often free)
Although you can ask your doctor for a virus test, you may be able to arrange to get a virus test for free from your state or local government. You can also go to a diagnostic laboratory or testing center, including some pharmacies. The test may be covered by your insurance or the government based on an assessment of your risk level. Here are some examples of testing programs around the country. 
  • Project Baseline works with community based screening programs in locations in several states to offer free virus testing. You must fill out an online questionnaire and be accepted. You will then be given an appointment at local testing center where a sample will be collected with a self-nasal swab or a nasopharyngeal swab. The project is sponsored by the parent company of Google through its health unit, Verily, and a Google email account is needed to complete questionnaire online. 


  • Rite Aid Pharmacies in some locations are participating in Project Baseline, providing testing at no cost to anyone 18+ years of age.


  • CVS (including MinuteClinic and HealthHUB) had originally offered drive-up, rapid testing using the Abbott ID NOW system, a small, portable device that yields results in 13 minutes or less. Unfortunately, this system was been reported to yield a high percentage of false negative results due to lower sensitivity than other systems. That is, a negative result may need to be confirmed using another test (Basu, bioRxiv 2020 preprint). (For more details, see Finding the Best COVID-19 Test, below). Virus testing is still offered, but specimens are now sent to independent, third-party labs for processing, and test results are available in approximately three to four days.


  • Walgreens offers drive-up testing in which you perform your own nasal swab. You sample is sent to a laboratory and you are notified by email or phone when results are available. (Originally results were promised within 24 hours).


  • Kroger Health offers public drive-thru and walk-up COVID-19 testing.
At-home sample collection
  • Pixel from LabCorp allows users to collect their own nasal swab samples and mail them to LabCorp for testing. This product costs $119. It was initially only available to healthcare workers and first responders but is now available for consumer purchase. No prescription is necessary, although you need to complete a simple online questionnaire and meet eligibility criteria demonstrating need for the test. You may be covered by your insurance for the cost. Due to state restrictions, it is not be available in Maryland, New Jersey, New York and Rhode Island.


  • Everlywell COVID-19 Test Home Collection Kit ($109) is sent to users after completing an online eligibility questionnaire. The kit allows users to collect their own nasal swab samples. Samples are then sent directly to an accredited laboratory. The company promises online results within 3-5 days from purchase and results are reviewed by a physician. It is not available in Maryland, New Jersey, New York or Rhode Island.


  • Kroger Health COVID-19 Test Home Collection Kit is currently available to Kroger employees and will soon be available to non-employees. Based on results of an online screening, a healthcare professional will issue a prescription and the home collection kit is shipped to the home within 24-48 hours. The home collection kit includes a nasal swab, transport vial, instruction sheet, prepaid shipping label, and packing materials for return shipment of the sample to the laboratory. Upon receipt of the home collection kit, a healthcare professional guides the home collection process video chat. The patient will then ship their sample overnight to Gravity Diagnostics, which has developed an FDA authorized virus test yielding results 96.8% and 100% in agreement with the CDC's own tests, respectively, on positive and negative samples. Results are provided online or by phone within 24-48 hours.


  • Rutgers Clinical Genomics Laboratory allows users to collect their own saliva sample using a special collection device and return it for testing at Rutgers. This test requires a prescription.
Antibody Test
As with virus tests, many laboratories have received FDA approval to conduct antibody tests, some of which are very accurate. Although the FDA has not approved or authorized rapid, home tests for antibodies, many such tests are available in other parts of the world and some have been sold in the U.S.

Through a local healthcare provider
Your healthcare provider can arrange for you to get an antibody test if deemed appropriate. Blood would be drawn either by your provider or at nearby diagnostic laboratory. Similarly, many walk-in, urgent care centers can arrange for you to have the test, for a fee, which may be covered by your insurance. The samples are typically sent to a commercial laboratory, so results can take a few days. 

Consumer-initiated testing
Be aware than in many cases, the cost of antibody tests may be covered by insurance if ordered by your physician or health care provider. Some labs will require payment for consumer-initiated tests, while others will bill your insurance. Be sure to check the payment policy of the lab you plan to use if requesting your own test. You can also check if your insurance company covers COVID-19 testing. Medicare often covers the full cost of COVID-19 virus and antibody tests. If you are uninsured, health care providers can submit a claim to have virus and antibody tests covered by the Families First Coronavirus Response Act.

QuestDirect allows consumers to request a COVID-19 IgG antibody test and pay for it online ($119 plus a $10.30 physician oversight fee). An appointment is made for a blood draw at one of Quest Diagnostics 2,200 patient service centers and test results are available online one to two days later. Interested consumers must not have experienced symptoms of COVID-19 for at least 10 days. Quest has stated that the testing will initially rely on antibody tests run on the Abbott Architect and EUROIMMUN systems.

Labcorp also allows consumers to request a test directly through its website. According to the website, there is no up-front out-of-pocket cost for consumer initiated tests, but you will be charged a $10 fee for physician oversight services (there is no physician oversight fee if the test order comes directly from your own physician or healthcare provider). Labcorp will "bill the cost of the COVID-19 IgG antibody test directly to your insurance carrier, or if uninsured, to the appropriate government program." Antibody tests offered by Labcorp include Abbott SARS-CoV-2 IgG assay and Roche Elecsys Anti-SARS-CoV02 (IgG).

The American Red Cross announced that it is providing free antibody testing, with a 7 to 10 day turnaround, to those who donate blood. The test used is Ortho-Clinical Diagnostics VITROS (IgG).

You can see how each of these tests compare in the Finding the Best COVID-19 Test section below.

Rapid, home tests
The FDA has not yet approved or authorized of the use of any rapid, home antibody tests but several have been approved by the European Union, which provides its CE mark (Conformité Européenne) and/or by the Chinese National Medical Products Association (NMPA). In addition, research groups have been evaluating these tests. Some of these tests have been marketed in the U.S. without FDA approval or allowance. 

Finding the Best COVID-19 Test

There are now more than 90 virus tests and 22 antibody tests for COVID-19 authorized by the FDA. ConsumerLab has reviewed the data on their performance and assessed which appear to be the best antibody tests for COVID-19. We've added this information for ConsumerLab members. Sign in as a member or become a member now to learn how specific brands of virus and antibody tests compare, which currently appear to be the best, and where to get them.

What Does a Negative Antibody Test Mean?
If you took a coronavirus antibody test and it came back negative, it can mean one of several things:
  • The test was not sensitive enough to detect antibodies that existed. This is more likely if the test had a sensitivity of less than 100% (see Finding the Best COVID-19 Test — Antibody Test for sensitivities of FDA-authorized tests);
  • You may have never had COVID-19;
  • You took the test too early -- generally less than 20 days after first disease symptoms, although, according to the CDC, some people may take longer; or
  • You didn't develop levels of antibodies high enough to be detected by tests -- which preliminary research suggests may happen in mild and asymptomatic cases (Long, Nature Med 2020).
There is currently not enough data to know if a negative result could result from taking the test too late. More research is needed to determine how long significant levels of antibodies to SARS-CoV-2 persist.

The CDC cautions, "Regardless of whether you test positive or negative, the results do not confirm whether or not you are able to spread the virus that causes COVID-19. Until we know more, continue to take steps to protect yourself and others."

This article will be updated as new information is obtained.

Learn More About Coronavirus (COVID-19)



What are natural remedies for coronavirus (COVID-19)? Do supplements like zinc, vitamin C, or herbals work? >>

Does heat kill coronavirus (COVID-19)? Can it disinfect face masks and packages? >>

How can I make a mask that is as good as a surgical mask or an N-95 mask? >>

Should I wear a face shield to protect from coronavirus (COVID-19)? >>

Do UV light sanitizing wands and boxes kill coronavirus (COVID-19)? >>

Can I get the new coronavirus (2019-nCoV) from supplements from China? >>

I read that famotidine (Pepcid) may help treat COVID-19. Is this true? Are there risks with taking famotidine? >>

How are you staying healthy during the coronavirus pandemic? >>

See other recent and popular questions >>
COMMENTS

Jane20475   July 29, 2020
Is it true that Covid 19 anti body tests can come back positive if one has had a recent common cold?

ConsumerLab.com   July 30, 2020
It's possible that a COVID-19 antibody test with low specificity may detect or show positive results for other viruses that can cause respiratory infections (including colds), such as other coronaviruses. However, this should not occur with COVID-19 antibody tests shown to have 100% specificity. See our table for the best antibody tests, i.e., those with 100% specificity and sensitivity.

esther20401   July 15, 2020
Do any of the more accurate antibody tests provide the consumer with a specific number related to antibody levels? Or all they all positive/negative/inconclusive?

ConsumerLab.com   July 17, 2020
We've added information about this; see "Types of COVID-19 Tests -- Antibody test" in the answer above.

Doug20373   July 12, 2020
Is this statement from above accurate?

Note that in a population where few people (e.g., 5%) actually have antibodies, a test that is not at 100% on specificity, such as the test from Healgen that provides 97.56% specificity and 100% sensitivity, a positive result may only be correct 67.8% the time, although a negative result would nearly always be correct.

If specificity is 97.56% why only correct 67.8% of the time?

ConsumerLab.com   July 14, 2020
A good way to understand this is to imagine, for example, a population in which no one is infected. If a test is less than 100% specific, it will sometimes show a positive result when a person is negative. Consequently, a positive result would actually be wrong 100% of the time. So, you can see how, with a test with 97.56% specificity, positive results would be wrong 67.8% of the time in a population where few people have the virus.

Lori20372   July 12, 2020
Can you talk about test results coming back "inconclusive" for Covid?

ConsumerLab.com   July 14, 2020
Although the U.S. CDC does not post guidance regarding inconclusive results, the National Health Service in the UK explains the following: "An unclear, void, borderline or inconclusive result means it's not possible to say if you had coronavirus when the test was done. Get another coronavirus test as soon as possible if this happens. If you had a test because you had symptoms, you must keep self-isolating and have another test within 5 days of your symptoms starting." (https://www.nhs.uk/conditions/coronavirus-covid-19/testing-and-tracing/get-an-antigen-test-to-check-if-you-have-coronavirus/)

Lazar20360   July 12, 2020
My daughter and her husband both were sick with covid-19 and now, two month later both tested positive for covid anti-body. However, among their small children who did not have any symptoms, only one out of three tested has anti-body. Which seems to confirm that asymptomatic people don't develop AB.

ConsumerLab.com   July 14, 2020
There several reasons why someone may get a negative result with a COVID-19 antibody test. Please see "What Does a Negative Antibody Test Mean?" in the answer above.

jirayr20341   July 8, 2020
Co-Diagnostics company in Utah has a 100% sensitivity and specificity test for Covid-19.

ConsumerLab.com   July 8, 2020
The FDA lists their virus test (not an antibody test) as authorized and, according the data submitted by the company to the FDA, it does appear to be highly sensitive and specific.

Alexandra20339   July 8, 2020
Hi, do you know if people that have the antibody (have been infected), have been re-infected again with the virus?

ConsumerLab.com   July 13, 2020
According to the CDC: "We do not know the degree to which previous COVID-19 illness protects against a subsequent SARS-CoV-2 infection or for how long persons are protected. Currently, serologic testing cannot be used to determine if this person may be reinfected. A positive serologic test may be evidence of the prior infection, but it remains unknown to what degree persons with detectable anti-SARS-CoV-2 antibodies are immune to reinfection." (See https://www.cdc.gov/coronavirus/2019-ncov/hcp/faq.html).

Susan20181   June 14, 2020
Which tests are being used by Verily (Project Baseline )? I'm curious to their quality compared to some of the other tests you mention.

ConsumerLab.com   June 15, 2020
Project Baseline, run by Verily, is a system for setting up sample collections and getting results to patients. Likely some population data analysis as well. Each site may use a different lab and virus test -- all appear to be PCR based, i.e., looking for the genetic material of the virus. The project is focused on testing people for the virus, not antibodies. Hope that helps. For more information, see this page: https://kstatic.googleusercontent.com/files/9e312e8f06b6da01f1fda3e0f52d0622a3e51dcdf5afe3d085a232f66098e17b18b31cf67cbee029ff0796bacbfb21af88c099d63a60ec0c1bd3ca4bb4bc3713

Alan20161   June 11, 2020
Isn't Covid-19 too new of a disease that it is unknown that even if you have the presence of antibodies to the virus it does not indicate immunity?

ConsumerLab.com   June 11, 2020
It's still an open question, but the antibodies likely indicate some level of immunity. Not the kind of thing that can be ethically tested in a clinical study on people, so we need to wait for enough population-based data over time to know for sure.

Nora20155   June 10, 2020
You are doing a wonderful job in covering various important aspects of this corona virus epidemic, including evaluating protective gear, testing, benefits of supplements. This is information people really want to know, and you assemble this in a very helpful way. I am grateful for your extended coverage from supplements to other aspects of protecting our health and increasing our knowledge of what is available.

ConsumerLab.com   June 10, 2020
Thank you for letting us know!

Cynthia20154   June 10, 2020
This page should be available to the public as a public service, not just to those of us who subscribe to CL. If it were, I would post a link to it on Facebook etc. -- which would be advertising for CL. Please consider this.

ConsumerLab.com   June 13, 2020
A free version of this page is available to non-members, but additional information (regarding identification of the most accurate antibody tests and where to get them) does require CL membership. Membership funds our ongoing work.

Gene20152   June 10, 2020
Mayo Clinic says they've developed their own approved tests and I know specimens are being sent there from other states. Are those tests in this table?

ConsumerLab.com   June 13, 2020
Please see our response on June 3 to a similar question in this section.

hilary20150   June 10, 2020
Greetings! What a remarkably clear, concise and helpful article - very impressive! I have been looking for this kind of summary with no luck until now. Thank you!

ConsumerLab.com   June 10, 2020
Thank you for your kind words. We're glad you're finding it helpful.

kendra20092   June 1, 2020
I had tried in past to understand these concepts, but it was murky. I finally watched this video and understood this important info about the accuracy and usefulness of the new antibody tests. this is first explanation of the issue (and math) and what it means that is so clear that I could understand it.

"There is new information from the CDC that COVID 19 antibody testing in populations with a low prevalence of infection results in a high number of false positives (even if the test has a specificity of 95%). Dr. Seheult illustrates why the positive predictive value (and negative predictive value) are generally more helpful than sensitivity and specificity alone (This video was recorded on May 28, 2020) "

Coronavirus Pandemic Update 76: Antibody Testing False Positives in COVID-19 - YouTube
https://www.youtube.com/watch?v=NSRK41UbTEU&list=TLPQMjgwNTIwMjAxOSFRpLFKrQ&index=3

ConsumerLab.com   June 4, 2020
Keep in mind that the real probability of a test result being correct for an individual is best determined by the particular circumstances of that individual, as well as the sensitivity and specificity of the test used. For example, has the person exhibited signs of the disease or not, or have they been in high-risk situations or not. The positive and negative predictive values are based on disease prevalance in the population, which won't necessarily reflect the circumstances of the individual. A general discussion about this is found on Wikipedia at https://en.wikipedia.org/wiki/Pre-_and_post-test_probability.

kendra20091   June 1, 2020
Which antibody test is being used in Minnesota by Mayo Clinic? I thought it was a serum test that Mayo developed themselves, but I do not recognize a Mayo test in your list. thanks for tracking this info. I had searched online and found this info on sensitivity and specificity impossible to locate for each test.

ConsumerLab.com   June 3, 2020
Mayo Clinic seems to be using an antibody test (for IgG) from Epitope Diagnostics, Inc, according to this page: https://www.mayocliniclabs.com/test-catalog/Overview/609035. Currently, this test has not been evaluated by the FDA but is allowed, as it has been filed with the FDA -- you can find it on the list we discuss above. It seems to have been tested by researchers in Germany who found it to have 100% sensitivity (so no false negatives) although only 88.7% specificity (so some false positives) -- see the study at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7189838/. So, if you have antibodies to the virus, it will detect them. However, there's a small chance that a positive result is incorrect.

Iver20082   May 31, 2020
Thanks for synthesizing this information in one place! When we say a test is for example 95% sensitive we mean that of 100 people *known for certain to have a disease*, the test correctly identifies 95 of them (95% true positives). Saying this implies there's a test or situation that is by definition always correct (a gold standard to which other tests are compared). What's the gold standard for COVID-19 antibody testing? For example, might we find 100 people who had positive PCR tests (and a consistent clinical picture), then do antibody tests on them 3 or 4 weeks later? If 95 of them had a positive antibody test, would we say that particular antibody test was 95% sensitive? (And would specificity be established in the same way - find 100 people with consistent negative PCRs and no symptoms, and then some weeks later if 5 of them had antibodies would we say the test was 95% specific?). I asked an epidemiologist this question and they agreed it could be done this way but they weren't sure that was how labs actually got their sensitivity and specificity figures. Thank you!

ConsumerLab.com   June 4, 2020
The best explanation of how sensitivity and specificity are being measured with COVID-19 antibody tests is that provided by the FDA on the page we linked to above (full version): "The performance of these tests is described by their "sensitivity," or their ability to identify those with antibodies to SARS-CoV-2 (true positive rate), and their "specificity," or their ability to identify those without antibodies to SARS-CoV-2 (true negative rate). A test's sensitivity can be estimated by determining whether or not it is able to detect antibodies in blood samples from patients who have been confirmed to have COVID-19 with a nucleic acid amplification test, or NAAT. In some validation studies of these tests, like the one FDA is conducting in partnership with NIH, CDC, and BARDA, the samples used, in addition to coming from patients confirmed to have COVID-19 by a NAAT, may also be confirmed to have antibodies present using other serology tests. A test's specificity can be estimated by testing large numbers of samples collected and frozen before SARS-CoV-2 is known to have circulated to demonstrate that the test does not produce positive results in response to the presence of other causes of a respiratory infection, such as other coronaviruses."

william 20046   May 27, 2020
Excellent description of testing issues!

Folks mostly do not understand prevalence, sensitivity, specificity, and sero-conversion.

bill g, mph

ConsumerLab.com   May 27, 2020
Thanks. We're staying on top of this area, continually updating.

Jennifer19937   May 18, 2020
I've seen no mention anywhere of whether biotin supplementation will interfere with some of the antibody tests. I assume it's possible since Troponin, thyroid hormones, Hep A, B, and C antibody tests can be falsely negative if a patient is consuming biotin.

ConsumerLab.com   May 21, 2020
Large doses of biotin may interfere with COVID-19 antibody tests. We've added a note about this in the answer above. For information about biotin interference with other types of tests, see the Biotin section of the B Vitamin Supplements Reviewhttps://www.consumerlab.com/reviews/Review_Best_B_Vitamins_and_Complexes_Energy_B6_B12_Biotin_Niacin_Folic_Acid/bvitamins/#kummer.

Mark19912   May 14, 2020
Hoping there will be a review of the Quest antibody test.

ConsumerLab.com   May 14, 2020
As noted above, QuestDirect has stated that it is using the Abbott Architect and EUROIMMUN systems. The results for each are shown above in the "Finding the Best COVID-19 Test" section.

J.Claire19904   May 13, 2020
This is very interesting: the base rate fallacy, I admit I had never heard of it, but then I avoid statistics if I can. Does this mean even a antibody test 100% both sensitive and specific will have false positives?
https://www.nytimes.com/2020/05/13/opinion/antibody-test-accuracy.html?referringSource=articleShare

"Just Because You Test Positive for Antibodies Doesn't Mean You Have Them"

In a population whose infection rate is 5 percent, a test that is 90 percent accurate could deliver a false positive nearly 70 percent of the time.


ConsumerLab.com   May 14, 2020
A test that is 100% sensitive and specific should not create false negatives or false positives (if done correctly), regardless of the prevalence of disease in the community. But it is true that when the prevalence of a disease is low (i.e., few people have it), a test that not 100% specific could falsely identify more people as positive who are actually negative than who are actually positive.

Doug19899   May 13, 2020
Although this may not be your area of expertise, I'm looking for reasons why and why not to get a voluntary test. I'd like to know if I've been exposed, but if I was then what could happen to me? What could I be forced to do?

There is a story that anybody positive for COVID cannot join the military. I recall a reluctance in the population to be tested for HIV many years ago.


ConsumerLab.com   May 21, 2020
These are good questions with both medical and ethical implications and beyond the scope of this article. However, regarding your question about preclusion from military service, this appears to only be true if one has been hospitalized with COVID-19, not just for having tested positive for the virus or antibodies, as noted an article in Stars and Stripes on May 8: https://www.stripes.com/news/us/contracting-coronavirus-won-t-disqualify-you-from-serving-in-the-military-but-a-hospital-stay-for-it-might-1.628995

Lazar19887   May 13, 2020
You mentioned that some anti-body tests were approved by EU. Which ones? Are they available for purchase in U.S. for home use?

ConsumerLab.com   May 21, 2020
We have added a link to a list of tests that conform to the European standards and have the CE mark. Those tests may or may not be available in the U.S., although some have received both FDA allowance and the CE mark. See the full section, Finding the Best COVID-19 Test.

Jimmy19886   May 13, 2020
I had the virus for 5 weeks, even though I had 3 negative tests. I took my first test at the 2 1/2 week mark, nasal rapid test swab and it was negative. I continued to have symptoms and then 1 1/2 weeks later I took a 2nd swab test that got sent to the lab, negative again. At the 5 week mark, I got a blood test with Quest and it came back negative that I never had the virus or antibodies.

I know I had the virus as the symptoms were it to a T. How can we rely on any of these tests?

Gwendolyn20049   May 27, 2020
All of the usual viruses (influenza, etc) are still out there. According to one source, around 50% of the people who were absolutely SURE they had had COVID-19, did not have any antibodies. A PCR test for Covid-19 would not diagnose other viral infections.

Eve20054   May 27, 2020
I had a similar experience. I then realized that I take a lot of supplements including Vit B Complex and other supplements which contain biotin which CAN cause the COVID tests and antibody test to not work correctly. Do you take supplements for nails and hair or others that may contain high levels of biotin?

Jimmy20147   June 10, 2020
I was actually taking a biotin supplement, which I stopped recently.

Mary20344   July 8, 2020
According to a recent article on CBC.CA, the tests used in Canada (PCR) are at BEST 80% accurate. That's a false negative one out of five times. And that's at the height of symptoms (somewhere around day 7 ). Accuracy decreases thereafter to something like 40% or even less.
https://www.cbc.ca/news/health/coronavirus-test-false-negative-1.5610114

Jim19881   May 13, 2020
Is it possible to get the virus sickness twice?

ConsumerLab.com   May 13, 2020
A big question, but there is no definitive answer as of yet.

Sandy19925   May 17, 2020
Hi: Looks like you can get reinfected according to this NPR article about sailors. "The U.S. Navy says 13 sailors from the USS Theodore Roosevelt who had apparently recovered from the coronavirus and had received negative test results have now tested positive for a second time.

In a statement released earlier on Saturday when five sailors were found to have retested positive, the Navy said the sailors had "met rigorous recovery criteria, exceeding CDC guidelines," including testing negative for the virus at least twice, but have now retested positive. The statement said the sailors had been monitoring their health and adhered to social-distancing protocols while on board the Roosevelt, which has been docked in Guam following an outbreak infecting hundreds of crew members.

"These five Sailors developed influenza-like illness symptoms and did the right thing reporting to medical for evaluation," the statement said.

The Navy has since confirmed to NPR that an additional eight sailors have retested positive for coronavirus, bringing the total to 13." https://www.npr.org/sections/coronavirus-live-updates/2020/05/16/857379338/5-uss-roosevelt-sailors-test-positive-for-covid-19-again

Marthe19872   May 11, 2020
I read your article about covid tests. I know someone who had symptoms and had 2 negative tests. She had trouble breathing and went to the hospital on Sat. Had a negative test and they sent her home. She went back to the hospital Sunday and died there.

Someone my daughter knows had a negative test and then tested positive and died. Makes me worry that these tests aren't accurate. What do you think?

ConsumerLab.com   May 11, 2020
Very sorry to hear that. It could have been the type of tests used, the timing of them (too early or too late), or, as you note, the accuracy of the specific tests.

Brenda20268   June 29, 2020
My Abbott antibody test was negative. Was it too late to take the test? It has been 3 months since I had very minor but untested symptoms. My Doctor said almost all the tests are coming in negative. What is going on??

ConsumerLab.com   July 7, 2020
We've added information about this in the section "What Does a Negative Antibody Test Mean?" in the answer above.

j19851   May 10, 2020
I would like to see your comments as to whether the antibodies actually offer protection from reinfection or not. Many are reporting/speculating that with rapid mutation and reported reinfections that we still are not sure about protection .

ConsumerLab.com   May 11, 2020
We, like you, also await definitive evidence on this question.

Caroline20479   July 29, 2020
Can you find information for us about T-cell immunity? How to get tested for it? Who is doing good research about it?

ConsumerLab.com   July 29, 2020
Information about T-cell immunity in COVID-19 is already found in our answer above, but there are currently no commercially available tests. Should one become available and be authorized for use by the FDA, we will add information about it.

Brian19849   May 10, 2020
Which antibody tests have received approval vs. EUA? There is a list for EUA companies but I have not found the list for approvals.

ConsumerLab.com   May 21, 2020
At this time, the FDA has not approved or authorized tests for COVID-19 virus or antibodies, it has only issued Emergency Use Authorizations (EUA) for such tests.

Judith19837   May 10, 2020
I've heard that the nasal swab is very painful. Is the saliva swab just as good?

ConsumerLab.com   May 11, 2020
A nasopharyngeal swab, in which a long swab is inserted far back through your nose, can be very uncomfortable. A nasal swab would not go far back and would cause little discomfort. Research is showing saliva to provide a sample that may be just as useful, although most tests at this time are based on nasopharyngeal or nasal samples.

Brian19868   May 11, 2020
A nasal swab should not be painful when using proper technique. One generally needs a tissue and may sneeze and/or laugh from the experience.


Share your thoughts and comments about this topic in the space below. Please abide by the following rules:
  • If you make a statement of fact, such as whether a type of treatment does or does not work, state your basis -- such as personal experience or a published study.
  • If you make a positive or negative comment about a product, note whether or not you have a financial interest in the product or in a competing product.
  • Please be respectful in your tone.
  • Please do not submit any type of HTML markup or scripting as it will not be accepted, nor will comments that exceed 2,500 characters.
For your privacy, only your first name (from your account) followed by a random number will appear with your comment. Your last name and email address will not be displayed.
Comment:

Share your thoughts and comments about this topic in the space below. Please abide by the following rules:
  • If you make a statement of fact, such as whether a type of treatment does or does not work, state your basis -- such as personal experience or a published study.
  • If you make a positive or negative comment about a product, note whether or not you have a financial interest in the product or in a competing product.
  • Please be respectful in your tone.
  • Please do not submit any type of HTML markup or scripting as it will not be accepted, nor will comments that exceed 2,500 characters.
For your privacy, only your first name (from your account) followed by a random number will appear with your comment. Your last name and email address will not be displayed.
Comment:

You can modify your comment below. Please be aware the comment will have to approve the changes before they will be shown:
Comment:

Your edit has been submitted and is being reviewed by ConsumerLab.com prior to publication.
This CL Answer initially posted on 5/9/2020. Last updated 8/8/2020.
ConsumerLab.com members may submit questions to CLAnswers@ConsumerLab.com. We read all questions and try to answer those of popular interest.

 

   BECOME A MEMBER
JOIN NOW

SPECIAL
Coronavirus Information Center
Coronavirus Information Center
Answers to Critical Questions About COVID-19.


Product Reviews

ENCYCLOPEDIA
In addition to our product reviews our encyclopedia covers the following:

Herbs & Supplements

Conditions

Drug Interactions

Alternative Therapies

MEMBER TESTIMONIALS

VISIT OUR PARTNERS


Follow us on...
facebook twitter
 
 
Join |  Sign In
   
Join Us on Facebook! Join Us on Instagram! Join Us on Twitter! Join Us on YouTube! Join Us on YouTube!
Product Reviews
Brands Tested
Health Conditions
Encyclopedia
CL Answers
Clinical Updates
News
Recalls & Warnings
Recommended Intakes
Where to Buy Products
Testing Program
How Products Were Tested
Quality Certification Program
Join CL Today
Testimonials
Join Free Newsletter
Group Subscriptions
Gift Membership
About Us
The CL Seal
CL Survey
Privacy Policy
Sitemap
Contact Us/Help

©2020 ConsumerLab.com, LLC. All rights reserved. A single copy of a report may be printed for personal use by the subscriber. It is otherwise unlawful to print, download, store or distribute content from this site without permission.
ConsumerLab.com name and flask logo are both registered trademarks of ConsumerLab.com, LLC. This site is intended for informational purposes only and not to provide medical advice.