COVID-19 Updates with Parsley Health
In response to the COVID-19 pandemic, our team will be interviewing experts from across the ecosystem to bring the HLTH community timely facts and updates.
About Dr. Robin Berzin:
Dr. Robin Berzin, MD is the founder and CEO of Parsley Health. A Summa Cum Laude graduate of the University of Pennsylvania, Robin completed medical school at Columbia University’s College of Physicians and Surgeons, and trained in Internal Medicine at Mount Sinai Hospital in New York City. She has also trained in functional medicine with the Institute for Functional Medicine. In 2011 she co-founded the physician communication app Cureatr and currently advises numerous startups in healthcare and wellness. Robin founded Parsley Health in order to make whole-body, transformative medicine accessible to everyone through better services and smart technology.
HLTH Team: Can you explain how antibody testing for COVID works?
Dr. Robin Berzin: Antibody testing works by detecting whether the specific types of antibodies in your blood match those that correlate with the virus responsible for COVID-19 (the SARS-CoV-2 antigen).
Antibody testing is the only known way to detect if you’ve had exposure to the virus in the past. For COVID-19 antibody testing, there are three different subclasses of antibodies that can be used including immunoglobulin M (IgM) which indicates active infection, immunoglobulin (IgG) which indicates recovery after an infection and immunoglobulin A (IgA) which indicates respiratory infection.
Antibody testing, in general, is not new. It is routinely used to check for things like HIV and chickenpox. But it’s important to note that not all tests are created equal.
Antibody tests that only look at only one or two of the subclasses of antibodies such as only IgG or only IgM are not as comprehensive as those that test for all three classes (IgG, IgM, IgA), and therefore those tests might miss detecting an infection. Furthermore, many low-quality rapid tests have flooded the market, leading WHO to make a blanket recommendation against their use until their quality has been validated.
HLTH Team: What is the accuracy of the tests i.e. any false negatives/positives? If someone tests positive for having had COVID, what does that mean for them in terms of immunity?
Dr. Robin Berzin: Every test and every vendor or lab will have a different specificity and sensitivity -- and with FDA’s loosening of regulations around these tests, it’s important for consumers and doctors to individually evaluate the quality of specific test they intend to use.
The test that Parsley Health has selected tests for all three subclasses of antibody: IgM, IgA, and IgG. Our test is 97.14% sensitive, 98.36% specific, which means for every 100 people that have been exposed to the virus, 97 of them will get a positive result. With this specific test the likelihood of a false negative is low.
But there is more to making a diagnosis than sensitivity and specificity. Doctors also need to know the prevalence of a disease in the population, since that influences how they trust and interpret the results. That’s one of the arguments for scaling up antibody testing: it will establish the disease prevalence. This is also the primary reason it’s important to work with a doctor to interpret antibody test results.
At this time, it remains unknown how long IgG antibodies will remain in the body and if they will protect people against getting infected again (like they do with chickenpox). The WHO has warned that we don’t yet know if antibodies protect against getting COVID-19 twice, but as we do more antibody testing we anticipate clearer answers.
HLTH Team: When do you expect that antibody testing will be rolled out on a larger scale?
Dr. Robin Berzin: Antibody testing will only be sustainable at a national level when a high-quality self-administered finger prick test is scientifically validated or FDA approved. This type of test will allow people to collect samples at-home, using methods commonly used by diabetics to check their blood-glucose levels. People who want to be tested will still need to work with their doctor to ensure that testing is completed in the proper window of exposure for the test to offer accurate results, but high-quality finger-prick tests will reduce some of the logistical hurdles while increasing scale.
Right now, the only way to do the COVID-19 antibody test while keeping an eye on quality control is to require the blood sample to be drawn by a licensed phlebotomist under doctor’s orders. To limit the potential spread of COVID-19 and respect “stay at home” orders, the best way to do that is to utilize mobile phlebotomy services, which come to patient’s homes to draw the sample. This mobile phlebotomy model is higher cost and not as easily scalable as an at-home finger prick test.
HLTH Team: Where will people be able to get these tests?
Dr. Robin Berzin: Parsley Health is currently offering COVID-19 antibody tests to members in the state of California, where mobile phlebotomy services are robust and enough PPE is in supply for safe sample collection. Our tests are only available via doctor’s orders, through a trusted CLIA-certified and CAP-certified lab, and we hope that other companies will follow the same model to ensure that the tests used are high quality and that the appropriate testing windows are targeted. We hope to scale our testing capabilities nationwide as soon as a high-quality FDA-approved finger prick test is available.
HLTH Team: Will different testing sites be using different tests or all the same?
Dr. Robin Berzin: Different companies will be using different tests -- and some will be more precise than others. What is available and where will change quickly as the FDA approvals change. The key things you should look for are: doctor ordered tests that look at at least two antibodies for accuracy (IgM, IgG) and ideally all three (IgM, IgG, and IgA), and make sure that you are doing the test in the appropriate window after exposure (at least 5 days). Lastly, it’s important to ensure quality sample collection, that the lab that is processing the sample is reputable, and that the sample is collected in the safest circumstances possible.
HLTH Team: How were the tests able to receive FDA approval so quickly? What is the clinical evidence behind them?
Dr. Robin Berzin: This is where things get complicated and it’s important to understand the nuance. Under emergency circumstances -- such as a pandemic -- the FDA is able to approve the use of tests by consumers prior to receiving an official FDA stamp of approval. That’s what’s happening right now with COVID-19 antibody tests.
What this means is that doctors can now prescribe COVID-19 antibody tests that have been validated (meaning enough tests have been collected to be statistically true) and after testing has been conducted the labs can submit to the FDA to review that validation.
Currently FDA recommends that health care providers continue to use antibody blood tests to identify who may have been exposed to the virus. But the onus of responsibility sits with health care providers to understand “the limitations of these tests and the risks to patients and the community if the test results are used as the sole basis to diagnose COVID-19.”
With this in mind, results from antibody testing should not be used as the sole basis to diagnose or exclude SARS-CoV-2 infection or to inform infection status. A doctor must clinically interpret the test and make a recommendation on care and whether follow-up testing is needed.
All of this will become clearer as more testing and FDA reviews are completed over the coming weeks.
HLTH Team: Will there be any costs incurred to the patients receiving the tests? Will they be billed through insurance?
Dr. Robin Berzin: Like the early days of COVID-19 swab testing, insurance companies haven’t quite caught up with the latest testing. Many tests going on right now are not covered by insurance yet, but we are hopeful that insurance companies will soon cover these tests without co-pays so that anyone who thinks they may have COVID can quickly and affordably get a test.
HLTH Team: Any misconceptions out there that you want to clear up about the antibody tests?
Dr. Robin Berzin: Testing is critical to understanding your own health and helping to slow the spread of COVID-19 infection. The more we get community testing out into the world, the faster we can help slow the spread of the disease. Knowing who and who has not mounted an antibody response is critical to our understanding of disease progression. While we don’t know if antibodies translate to immunity, these early tests, particularly the comprehensive antibody test like the one we offer at Parsley Health, will be part of the way that we learn about the virus and how to ultimately defeat it.