Until recently, we’ve been referring to “testing” purely as the tests that use a swab to sample the back of your nose to see if the COVID-19 virus is there. The test, most recently the “Abbott test”, is checking for the COVID virus “RNA” (like our DNA). Early test versions took 3-8 days to get results (backed up labs), and the ” Abbott test” now takes only up to 30 minutes for a result on site. Even newer versions are checking the the nasal cavity or the mouth saliva, but that’s not important for this discussion.
The question for this “Nasal RNA Test” is “who really needs to be tested and do we have enough tests to achieve that in Ohio and in the USA?” We will get to those answers in a moment, but reality says that we are testing 200,000 a day in the U.S. right now, so we are looking at maybe 1.5-2 million new tests a week over the next month. Assuming that, let’s say 3 million more are tested in the next month assuming increased production occurs, which assumes that overseas components remain available to Abbott. If so, we will have tested only a total of 2% of the USA population by mid-May and likely no more than 4% of the population by mid June with COVID-19 RNA tests. Even if production quadrupled in a month, which it won’t, we would only test a total of 25 million Americans by mid June, or 7.5% of the population. That proves that we cannot use COVID-19 RNA nasal or saliva tests to screen the population for “readiness to enter society”.
So who really needs to be tested? I was very pleased yesterday with Dr. Deborah Birx’s presentation on the “Opening Up America Again” guidelines. She clearly laid out the prerequisites to get back to work in our State: 2 weeks of a negative new case trend and the testing/contact tracing containment capability of the Ohio Department of Health.
IMPORTANTLY, she explained that testing does not need to be of the whole country or whole state or even of every worker. Ohio DOH merely needs to be prepared to test/contact trace the newly symptomatic worker/person rapidly and trace their contacts. She also stressed the need to be larger number repeated surveillance screening tests of “high risk populations”…in nursing homes and in high density urban clinics. THAT is the number of tests that we need in OHIO, not 11.7 million. We should have the COVID-19 RNA nasal swab tests to cover those…someone needs to ask whether we do at today’s press conference. What if we don’t? Can we not work? Is there an alternative?
This brings me to the 2nd kind of COVID-19 test, the “serological test” or “antibody test”. It is already widely available in the US, but there are a number of different manufacturers, and we don’t have FDA approval of any yet. Supposedly, at least one will be soon. Regardless, the others are being used. In Cincinnati, one doctor has tested 4,000 people in the last 2 weeks. So, what is this test and can it be “substituted” for the nasal swab test?
The antibody test is a very fast simple pin prick of the finger tip with 2 drops of blood sampled. Mine, in a drive through clinic, took all of 4 minutes. I had my result emailed to me in 30 minutes. It does not detect COVID-19 virus. It detects “antibodies”, made in your bloodstream to fight COVID-19. The charts I’ve attached here explain when these “fighters” show up in your blood after being exposed to COVID-19. As you can see, you can be infected for 5-14 days and be asymptomatic and contagious with a NEGATIVE antibody test. However, once symptoms like fever appear, the “early antibody” IgM is positive on the test, and this means that you are infected and almost certainly contagious. If the “late antibody” IgG antibody is positive on the test, then you have at least “had COVID-19″…if the “early IgM” is also positive, you are contagious, and if “early IgM” is negative then your positive IgG means that you are later in the disease and LIKELY not infectious/infected anymore.
Does the finger prick “replace” the nasal swab test? No, it doesn’t. What is its value, then? First, it can quickly screen a significant portion of the population for COVID-19 exposure and probable (at least short term) immunity. This would give us a better idea of how widespread COVID-19 is and what percentage of our population is now “immune” to infection. This will immensely help predict COVID-19 impact in the Fall and beyond if it “comes back”.
Second, the antibody finger prick test could be used in the recommended “serial surveillance groups” that we will be “testing”, ie- inner city high density clinics in Columbus, Cincinnati, Dayton, Toledo, Akron, and Cleveland. That said, the nasal swab test will still be needed for “early positive antibody results” to confirm active infection and for general screening of these high risk groups once a possible outbreak is suspected.
Finally, the antibody test can detect those who are positive and recovered, who can now donate their “plasma” which can be given to treat the very sick with COVID-19 with antibody “fighters”. That’s why a doctor friend of mine and I got tested…we both had flu or COVID-19 symptoms in late February after travel. I was negative for antibodies. He was strongly positive. He is donating his plasma. My plasma is worthless 😂😞.
Sooooo, in summary, availability of both nasal swab virus detecting and finger stick antibody tests are essential as we go back to work. I believe that we have enough to get started in Phase 1 of “Get Back To Work Ohio” at this time, but Governor DeWine and Dr. Acton have to clearly confirm that they are prepared on their end today. We do not need to test everybody, so our lack of 330 million tests is not a problem. We need to test the worker/person with fever +/- other symptoms of COVID-19 rapidly and identify/notify all their close contacts, who must also get tested, IMO. We need to do repeated surveillance tested of the vulnerable, as per the Federal Guidelines: nursing homes and high density urban clinics. Both tests will have a role to play, only the finger stick antibody test will be able to determine how widespread our exposure/immunity is at a point in time, and the nasal swab virus detecting test cannot be “replaced” by the antibody test.