March 30, 2020
We have all heard about the tests that are in such short supply. It is the stuff of nightmares for hospital workers. For small businesses hoping to reopen in the foreseeable future, it is only part the equation. There are two categories of tests that we will explore today, the first category determines infection, and the second determines immunity.
The tests that are generally being referred to at this point are those that determine the presence of the virus. These are PCR (polymerase chain reaction) tests, or molecular tests. They involve nasopharyngeal (nasal) and oropharyngeal (throat) swabbing to determine if a person is carrying the genetic material of COVID-19. That is, whether or not the person is sick. Of course, under current conditions, most people being tested are demonstrably sick, and the question is whether they are sick with COVID-19. However, once there is an ample supply, these tests could be used to determine the presence of the viral RNA (riboneucleic acid) whether or not the person was symptomatic.
The main problem with these types of tests, when considered in terms of administration, is that they are technically complicated, and the possibility of false results due to operator error would be high if an attempt was made to utilize them in situations lacking properly trained technicians. For those that aren’t familiar, PCR, or molecular, testing starts with getting a sample. In the case of COVID-19, the sample consists of material collected via swabs from a person’s nose and throat. That sample is mixed with reagents. Reagents essentially stimulate the sample, causing it to react. In this case, the reaction is the breaking open of viral particles, which provides access to their RNA. Reagents need to be specific to the virus that is being tested for, they are not one size fits all. If the virus being tested for is present, the virus is replicated until it reaches easily readable levels.
In pursuit of a simpler alternative, a Canadian laboratory, Sona Nanotech, is working on a test that will be especially appropriate for use in-home and at points-of-sale. The technology they are working with is referred to as a lateral flow test, and according to their website, their expectations are that this test will be highly accurate due to both design and simplicity of use. Sona is developing a lateral flow test (think pregnancy tests) that will be specific to COVID-19. Like pregnancy tests, it is designed for administration by a lay-person. Although not yet available, a test such as the one Sona is developing could be the gold standard for businesses wanting to reopen safely.
A lateral flow test, as the name implies, involves having a sample flow over, or through, a test strip. The test strip will include a reagent, and often an antibody (or antibodies) to the antigen being tested for. An antigen is something toxic or foreign to the body, such as a virus. Because specific antibodies are attuned to their specific antigens, a reaction from a Covid-19 antibody will indicate the presence of that virus, and no other. The result will then be indicated on the test itself in the result window, as in a pregnancy test.
Another kind of testing that is not yet foremost in our collective thoughts, but will be, is serological (serum-based) testing. This type of testing determines whether antibodies to COVID-19 are present in the blood. Antibodies occur in response to a virus, whether because a person has been infected at some point, or because of vaccination. Of course, we don’t have a vaccine yet, and the timeline for development is longer than we would like. This means that anyone carrying antibodies to COVID-19 has had the virus. It also means, assuming the amount of antibodies present is sufficient, that these people should now be immune.
Immunity will be a matter of some significance to businesses looking to reopen. From the perspective of a business owner, knowing potential customers have developed immunity is a priceless benefit. From the customers’ perspective, knowing staff at an establishment has established immunity would be an immensely powerful factor in determining which restaurant, for example, to patronize.
The fact that we, as yet, have no vaccine means that our first category of tests would still be a useful tool for businesses. At least one on-the-spot test has been approved for emergency use by the FDA. It was developed by Abbott, and provides positive results in five minutes, with negative results in thirteen minutes. Although they plan to produce five million tests in April, those will certainly be going to medical professionals. At some point, the deficit of tests will be corrected and then other businesses will have the opportunity to incorporate point-of-sale testing, giving them the power to ensure customer and staff safety.
Until a vaccine is developed, we will have to rely on testing to keep public interactions safe. That means, business owners will have to consider what makes sense for their venue as far as cost, ease-of-use, and availability. While we continue to explore the ramifications of COVID-19 and the possible solutions, we, as always, want to hear your input. Each business owner, manager, and staff member will have a unique point of view on this issue. We want to hear yours.