- Virus– a type of germ that consists solely of a bit of genetic material (DNA or RNA) wrapped in a protein coat. The coat gets the genes into the target cell where the genes force the cell to make zillions of new viruses (genes and protein coat), and on it goes.
- Variant- also known as a mutation, a variant strain of a virus is the same species of virus but with a change in the genetic code. The change is minor if it has no impact on contagious the new variant is, or how deadly it is, or if it allows the virus to neutralize our vaccines. Variants that substantially increase harm are now listed by Greek letters, the most troublesome one now is Delta.
- Coronavirus– a species name of a number of different viruses. Called corona because its protein coat is studded with spike shapes that form a crown, halo, or corona of spikes
- SARS-CoV-2– the specific name of the new coronavirus
- COVID-19-the name of the illness that the new coronavirus is causing
- Endemic– an illness always present in a region. One could say strep throat is endemic in the US
- Epidemic– a sudden burst of an illness that comes and goes over a limited time
- Pandemic– an epidemic that bursts across the world not just one region
- Spreadability– how contagious is the disease, how many people will end up infected
- Symptoms- the experience of being ill, for example- fever, cough, headaches, loss of smell etc.
- Asymptomatic– literally means “without symptoms”. For COVID-19 it refers a person infected with the virus but has no and will have not symptoms
- Presymptomatic– This is a person who was infected with SARS-CoV-2, and will feel sick, but hasn’t yet
- Severity– what harm does the disease cause, in terms of how sick you get and how many it will kill
- Mask- a mask is a loose-fitting cloth or textile that covers the mouth and nose loosely. A surgical mask is a mask used in surgery
- Respirator- for the purposes of the COVID-19 pandemic and other respiratory illnesses, a respirator is a mask that fits very snugly or tightly to the user’s face. An N95 mask is a respirator.
- Live Virus Swab– this is the swab which attempts to swipe live virus from one’s nose or throat to see if you are currently infected.
- Antibody Test- (aka serology test) this is the blood test which looks for antibody to the SARS-CoV-2 virus to see if you have been infected in the past.
- Vaccine or Immunization– a dose of a substance that activates your immune system, as if you have the actual infection you are hoping to prevent, leaving you in fact protected from having that infection.
- Efficacy– the percentage of people immunized with a particular vaccine who will not get infected if exposed to the target infection. For example, a COVID-19 vaccine will be said to be 95% effective if 95% of people immunized with that particular COVID-19 vaccine will not get COVID-19 if exposed to COVID-19
- mRNA– DNA works by dictating exactly which proteins your cell will make. The message on how to construct each protein is delivered to the cell machinery that makes proteins by a piece of genetic material called messenger RNA, or mRNA
- mRNA vaccine– an mRNA vaccine places a small bit of mRNA code that makes your cells make a protein that is the protein from a virus that alerts your immune system and activates it to make protections against you being infected
- Viral vector vaccine– a viral vector vaccine takes a harmless virus that is known to infect people reliably and places that weakened virus in a person where that virus will in fact infect the person. The virus is not only weakened, but also attached to a set of genes that makes your cells make a protein that is the protein from a virus that alerts your immune system and activates it to make protections against you being infected.
A Review of COVID Testing
Just about everyone knows that you can be tested to see if you have COVID. But a lot of questions are coming up about PCR, about rapid, about antibody testing, so we thought now would be a good time to offer a review.
There are two really important reasons to be tested for COVID:
- To see if you have COVID and make sure you get the medical attention having it requires
- To protect those you love from catching it if you do
How do tests work?
All COVID tests try to accomplish the same thing, take a sample of something from your body and see if the SARS-CoV-2 virus left any trace of being there.
The COVID tests available today are able to look for 3 types of clues that the virus is present, or was present:
- The gene of the virus, these tests use nasal or oral swabs to see if any RNA of SARS-CoV-2 virus is present. This is the PCR test. PCR is a technique that copies genetic material so many times, it can be detected.
- The protein of the virus, these tests use nasal swabs to see if any of the protein on the coat of the SARS-CoV-2 is present. This is the rapid, or rapid antigen test. An antigen is any protein that is of interest to an immune system.
- Your own antibody to the SARS-CoV-2 virus, these tests take your blood and see if your own immune system has generated antibody to COVID. This is the antibody test.
The PCR test
The PCR test only turns positive if a swab swipes some viral RNA, or the genetic material of the COVID-19 virus from your nose or throat. If no virus is present, it will of course fail to swipe some RNA. But even if the RNA is present, it may fail to swipe it and collect it.
The PCR test can only be done by a health care facility, not at home.
And so, if the PCR test is positive, you can be highly confident you have COVID or had it recently. It is very hard for this test to turn positive if you do not have the RNA of the virus in your nose or throat.
But there are many paths to the PCR being negative, all the result of the swab failing to collect COVID viral RNA:
- You may not have COVID. If you don’t have COVID, you will have no COVID related RNA in your nose or throat, and the PCR will be negative.
- You may have COVID but tested too early. It takes about 5 days for the SARS-CoV-2 virus to make enough zillions of copies of itself to leave plenty of COVID RNA to detect. If you are infected with COVID say on December 1, and test on December 2, you will have a 100% chance of testing negative, even though you have COVID, not enough RNA will be present to detect. That is why we say the PCR is not reliable until 5 days after the contact you are testing to see if you caught it. Symptoms take about 5 days to appear too, so if you have symptoms, this reason for a negative test will not be relevant.
- You may have COVID but the swab missed picking up the RNA in your nose or throat. This happens, and is the reason a good PCR test, done with symptoms OR 5 days after contact, in someone with COVID can still be negative. This is a problem that happens about 10-20% of the time someone with COVID is tested.
FOR THE PCR TEST: A positive is reliable proof you have COVID, even if repeat tests of any sort are negative. The PCR test can remain positive for weeks, so we do not recommend retesting to prove you are not contagious. Since there are plenty of false negatives, if you are exposed to COVID directly, and are in quarantine, a negative PCR test DOES NOT mean you didn’t catch it, you must complete your quarantine.
The Rapid Antigen Test
The rapid antigen test turns positive if a protein in your nose or throat looks like proteins on the coat of the SARS-CoV-2 virus.
The rapid antigen test is done everywhere- at home, in drugstores, and in doctors’ offices and hospitals.
The problem with the rapid antigen test is that some other viruses other than SARS-CoV-2 viruses make proteins like the one detected by the test. In fact, the SARS-CoV-2 virus is a new coronavirus, but there are 4 very old coronaviruses that cause lots of colds. These 4 old coronaviruses cause about 25% of all common colds, and have done so for over 8,000 years!
As a result, about 25% of the time the rapid antigen test is positive, you do not have COVID. But, if you repeat the test and it is positive twice, for some reason, that drops that number dramatically, and now you can have confidence you have COVID.
The rapid antigen test can be negative for the same reasons as the PCR- you don’t have COVID, you tested too early, the swab missed the antigen. But it performs far better than the PCR if negative, about 99% of the time it is negative you do not have COVID.
FOR THE RAPID ANTIGEN TEST: This is a great test. It is rapid, it is getting cheaper, it is getting more and more available. If it is positive, you should do it twice. Positive twice you can be confident you do have COVID. A positive followed right away with a negative, you very likely do not have COVID. A negative test is very, very reliable sign you do not have COVID.
The COVID Antibody test
The COVID antibody test looks for evidence that your own body made antibodies to the SARS-CoV-2 virus.
There are a host of reasons that make the antibody test result essentially useless, except in very specific situations.
We know that most people make antibodies to this virus if you have had COVID, but it is not known how rapidly they appear and then fade, in each person. As a result you could develop COVID say on March 1, and not have antibody appear for 4 days, or 2 weeks, or a month. Your antibody level might rise high, or not high at all. Your antibody production may go on for a few days, a few weeks, a few months, or a few years. Kids don’t make as much antibody as adults. Even people with antibody may go on to have a re-infection. And, our bodies make all sorts of antibodies having nothing to do with COVID, and some of these may turn a COVID antibody test positive.
This variability means we simply do not know if a negative antibody test means you never had COVID. And, we have no idea if someone with a positive antibody test is at risk for catching it again and spreading it, or even if they actually have COVID.
The three special situations where antibody testing could be helpful are: if a child is suspected of having the incredibly rare MIS-C syndrome, if a blood bank is seeing if you can be a COVID antibody donor, and during vaccine trials.
FOR THE COVID ANTIBODY TEST: The meaning of a test result is nearly useless in normal situation, at this point, the ID experts at the Cleveland Clinic are being advised not to do this test. It is popular, but can be very, very misleading. Even if we knew enough to make it useful, it is not designed to tell you about current infection, like the PCR and rapid antigen tests.
Hope Comes With Declines in COVID
Around the world, across the United States, and in Ohio, particularly NE Ohio, COVID numbers are dropping.
The early indicators from May and June that Delta burns hot and fast continues to prove true. Even in our relatively unimmunized South, the horrifying numbers are in steep decline.
It is too early to say if and when the Delta epidemic will really drop to negligible levels, but we are clearly moving in that direction.
Readers of Real Answers will recall the measure we have been tracking is the number of people diagnosed with COVID on a given day. We use the number of new cases per 100,000 in a given population. As you may recall, if that number is under 5, your community has very little COVID spreading. Once you get over 20, enough spread is happening, people need to take steps to be protected. As you go over 20 to 30, 40, and up, a very active COVID epidemic is raging. And over 80-120, medical systems get overwhelmed.
The South during this terrible Delta surge of the unimmunized reached over 120 cases per day per 100,000 people in each state!
Highly immunized states like Vermont and NY really never surged over 20-30.
Ohio, which is about 50% immunized, hit the number 60 on September 17, but today that number here in Ohio is 47 and dropping.
Another piece of very good news is that the widespread outbreaks in schools have not materialized in the NE Ohio areas! This is due to our higher rates of immunization and agreement to have kids masked, rooms ventilated, children tested. Places even in Ohio not doing these steps are seeing large school outbreaks of our children getting COVID.
So, it is too early to actually have any confidence in the pandemic receding finally, but enough evidence of retreat is in hand to have strong hopes.
Vaccination remains the #1 tool to stop COVID, so please, please, please, if you are not vaccinated, get vaccinated today, and when your 5-11 year olds can be, please vaccinate them ASAP!!!
- Three tests exist to determine your COVID status
- The PCR test- highly reliable for positive tests. Can be falsely negative if done too early, or even after 5 days.
- The Rapid antigen test- the home test- highly reliable negative test. If positive repeat right away and if positive you can be confident you have COVID, if negative, you do not.
- The COVID antibody test- not useful outside of research, blood banking, and MIS-C evaluation.
- We increasingly like the rapid antigen test for most purposes, such as a child with a cold. The kits are available at many libraries for free, at many drug stores. Plan to do two tests if the first is positive. You get results in 15 minutes. A great strategy is to do them often, before work or school, especially for any question of infection.
- The tragic Delta COVID epidemic is receding, maybe, just maybe, it will really go to near zero and no one mutations or variants will surge. We can hope.
- Meanwhile, COVID is NOT vanquished yet, and the only tool that will end it soon is COVID vaccination. It is SAFE. It is EFFECTIVE.
My One Takeaway Sentence:
If you are 12 or older and not COVID vaccinated, or when your children ages 5-11 can be vaccinated, please, please please get vaccinated ASAP, lives are literally hanging on you doing so.
To your health,
Dr. Arthur Lavin