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Day 86, COVID-19: I Take an Antibody Test
A SARS-CoV-2 antibody test kit being administrated, from Arcpoint Labs
The image is from the Arcpoint Labs website and shows both the SARS-CoV-2 antibody test kit and the way it is administered. Alcohol wipe the finger. Use a lancet to prick the finger and start oozing blood. Use a capillary tube to draw in some blood from the wound and place a droplet in the test kit port marked “lgG.” Repeat the draw and place a droplet in the test kit port marked “lgM.” Add reagent to the port marked “B” ( I think). Wait five minutes for results. They didn’t show me the kit when the test was completed so I can’t describe what it looks like when a result is given. Maybe it is some coloring of points marked “C” and “S” on the kit?
Mind you, this is not a test for the presence of the virus, like they give to symptomatic people. This is a test for antibodies against infection by the virus — and indicator that the virus has been in the system and defeated.
OK, what were my results? Negative for both lgG and lgM. The paper they handed out to explain the test results state as follows:
Negative lgG, Negative lgM (two possibilities):
• Patient has never encountered COVID-19 and is healthy, but susceptible. Continue social distancing protocols.
• Early latent infection — too early for antibody detection. Continue social distancing approx. 2 weeks.
Because they are testing for two antibodies there are four possible outcomes. The other three are:
Negative lgG, Positive lgM:
• Early stages of antibody response. Possible virus carrier/latent infection. Continue social distancing for
approximately 5-7 additional days.Postive lgG, Positive lgM:
• Recent infection. Suggests functional immunity. Discontinue social distancing.
Positive lgG, Negative lgM:
• Past infection. Suggests functional immunity. Discontinue social distancing.
Arcpoint is one of over 70 commercial labs that have or are developing COVID-19 antibody tests. I asked what was the minimum titer required to generate a positive test result? The technician did not know but said that was a good question.
None of the tests are FDA-approved at this point. And the fine print also says “Negative results do not rule out SARS-CoV-2 infection, particularly in those who have been in contact with the virus. Follow-up testing with a molecular diagnostic should be considered to rule out infection in these individuals.” That quote is FDA-mandated boilerplate along with “Results from antibody testing should not be used as the sole basis or diagnose or exclude SARS-CoV-2 infection or inform infection status,” “Positive results may be due to past or present infection with non-SARS-CoV-2 coronavirus strains, such as HKU1, NL63, OC43, or 229E,” and “Not for the screening of donated blood.”
So where does that leave me? It is suggestive that whatever else is going on, my particular perambulations have not brought me into contact with the virus. And, no, the flu-like symptoms all three of us in the household experienced in January was not COVID-19. We all had the seasonal flu vaccine and the illness we did have was pretty mild.
The county where we live in California, Contra Costa, is part of the greater Bay Area and has been in lockdown since March 17. We currently have 615 confirmed cases in the county, with 44 hospitalized and 14 deaths. The county’s population exceeds 1.1 million.
My community is away from the large population centers of the county. Which is just as well. The household is comprised of a 66-year-old female (Mrs. Rodin), a 70-year old male (me), and a 90-year-old female (Mrs. Rodin’s mother). Our infection control protocol is pretty much what you would expect from people our age — whatever our energy permits and whatever we can remember to do. Over the last couple of months, I filled up what had been bare freezers in case we had to be quarantined. We made sure we had 90 days of meds. I am the only one who goes to the grocery store or the pharmacy. I wear a mask when I am in any store and add gloves at the supermarket or gas station.
Mrs. Rodin’s mother accompanies me on as many trips as possible but only stays in the car. It keeps her from going stir crazy — and no one wants her to be stir crazy. As no one in the household was working outside the home when the health emergency was declared, the main impact has been the inability to do sit-down dining in the restaurants we frequented or the occasional visits to retail shops. It has scuppered any possible family visits for the time being. And broader excursions to Carmel, Monterey, Lake Tahoe, or regional and national parks are out of the question.
But we are not the ones I worry about. I fear for the many people who provided services to us that are now idled. I fear for people who need group support but who are barred from gathering. Mrs. Rodin asked me last night what are the people who need meetings to control their addictions doing? Fortunately, we do not have personal experience of this, but one of our favorite comedies, Mom, is centered around recovering addicts, so no doubt this prompted the thought.
There has been discussion on our Nextdoor local group about a shortage of produce in our local store. Speculation is that farmers are having problems getting the crops into the supply chain, or that maybe truckers are in short supply. I don’t know. This is probably temporary but I worry that a lot of damage is being done to the economy in ways that are not always apparent … until they are.
So, let’s get those antibody tests rolled out and getting a better picture of the level of infection and the true risks of getting this disease.
[Note: Links to all my COVID-19 posts can be found here.]
Published in General
I’m not ascribing that argument to you, just that this information bears on that argument as well.
That’s fair. I remain, as I keep saying, cautiously hopeful. There are so many contradictions in the facts, I can only assume that some of the facts are wrong. And while some scenarios are far better than others, any whittling away of incorrect facts will be helpful.
I haven’t yet found the link to the Washington retest as yet, but there’s some extremely detailed tracking of mutations of the virus here:
https://nextstrain.org/ncov/global?f_country=USA
That’s just for the US, you can get other countries or the world by using a pull down menu. Their US sampling goes back to the beginning of the year at least. With this level of detail, if there were earlier independent infections, they would probably be visible in the point mutations.
Aside: This is amazing stuff. It’s the kind of mutation tracking that’s done to figure out evolutionary pathways, and they are doing it in real time.
Heh. I’m an engineer, not an attorney. Current estimates of immunity level needed for herd immunity in the US are about 70%. So my 2.8% guesstimate would have to be off by a factor of 25 to reach that level. That’s a bet I’d take, to change metaphors, even given the acknowledged shortage of information.
That is a funny and true statement of this entire covid-19 event. :-)
Got it. Here’s the link to the Washington retrospective COVID testing – read the whole thread:
Link credit to – of all places – National Review.
Good advice in so many ways, most of which have nothing to do with COVID-19.
You cannot rest your case until you have tested your case
To be fair, I don’t expect full herd immunity- any level of herd immunity would be beneficial, and at a relatively small amount (I imagine), you start to get less of the extreme levels and things look a bit more manageable.
p.s. I apologize if that sounded snide.
The last paragraph estimates a case fatality rate between 0.5 percent and 3 percent. No way it’s 3 percent. At most it’s 1 percent imo. I will bet 3000 dollars the case fatality rate is under 3 percent
So… I’m less interested in herd immunity as such, and more interested in length of stay and how widespread it is. Take these 3 points together. 1) if the majority of cases are asymptomatic, and 2) it spreads easily (or easily enough to justify social distancing), with 3) it has been here since early February at the latest.
Honestly, I don’t know what “running it’s its course” looks like, and certainly not all viruses are alike. Certainly sars1 burned out before ever reaching herd immunity. Point being, as I said previously, these facts don’t all line up. Simmering for 6 weeks followed by exponential daily growth (right when we start testing)… So, some of our facts are wrong, because they cannot coexist. It isn’t at all clear which ones…
@rodin, you’re 70?? I never would have guessed. You look so young and athletic in your avatar. I guess some people just age better than others.
The first case in the US was in January.
The seed date was in November or December not early February
Yeah.
It’s a start, but lots of issues to work out
Other issues.
Once validated imagine the scrum that is going to develop to get tested if thats the key to returning to work. With the PCR test Utah at one point used up 80% of their tests on the Utah Jazz basketball team.
Just heard they expect “20 million tests by June”. Great, but there’s probably North of 200 million who want to be tested so they can go back to work.
Second. Those who test negative and want to work. What happens to them?
And how many in desperation will try and get infected, hoping for a mild case so they can convert and get on with their lives?
It sucks.
We didn’t have to be here.
There are no good answers or magic bullets.
One small detail you either don’t know or choose to ignore
CDC confirms first case of coronavirus in the United States
Updated on: January 21, 2020 / 6:01 PM
By Audrey McNamara
The U.S. Centers for Disease Control and Prevention has confirmed the first case of coronavirus in the United States. After returning to Seattle, Washington, from traveling in Wuhan, China, a man in his 30s began to experience pneumonia-like symptoms, the CDC announced Tuesday.
Does anyone know how often health care workers/hospital staff are tested? I would agree that without frequent testing, testing may not be as helpful as advertised. Mostly a way to bash Trump/Republicans?
I apparently made the non-scientist mistake of mixing antibody and flu test. However it would be interesting to look at all testing on hospital staff.
Immunity aside, it seems to me that widepread testing could be very important in that it will give us a better understanding of how dangerous the infection actually is. Given testing practices so far, it seems certain that the total number of people who have been infected is larger than we currently know; but how much larger? It’s possible that, even without immunity, the vast majority of people won’t get particularly sick.
If that’s true, it seems to me that the cost/benefit calculation changes a bit. If the risk posed by COVID-19 is no greater than the risk of being in a car accident — a risk most of us normally accept on a daily basis — then it starts to seem rather silly to go to such extreme lengths to avoid it.
I don’t actually expect the answer to be that extreme, but it could be. Point is, we don’t know.
First of all, based on the cruise ship incident, only 20% got infected in that optimal (for the virus) event. You will not get 70% “herd immunity” if 80% of people exposed do not get infected.
The French carrier Foch is apparently returning to port with a third of its crew infected. And those sailors will be largely a young and healthy population. I wouldn’t lean too heavily on that cruise ship data point.
I think your bet is safe. Here’s my current back of the envelope:
As of right now, 646300 positive test in the US, 28640 deaths.
Assume 7/1 ratio of total cases including asymptomatic & minimally symptomatic (nonpresenting) cases to positive tests (based on early Wuhan data) implies 4524100 actual infections.
28640/4524100 ~ .6%
Probably somewhat understated, since some unresolved cases will end in death, but far enough below 1% that it will probably stay there.
Here’s the down side of those numbers:
4524100 / 329,500,000 (estimated current US population) = 1.37% have been infected
To get to 70% level required for pure herd immunity (IOW, no other measures taken to reduce R-nought): (70% / 1.37%) * 28640 = 1.46 million deaths in the US
So we won’t do it that way. Social distancing, masking, isolation are going to be around for the duration.
I don’t know about young and athletic, but I certainly look metallic in my avatar.
Michael Levitt, biophysicist and Nobel prize winner in Chemistry, used the Diamond Priness data to form much of his hypothesis and modeling. He did not predict doom and gloom. In fact he predicted the opposite.
If French sailors are young and healthy then none of them will die, correct?
Metallica!
1.46 million deaths is wrong — too high
Let the children out! Children have strong immune systems and have not been affected by the virus. They are either immune or asymptomatic.
Yep, we here in Palm Beach County are hoping things get start opening soon. If they let workers back on building sites and homes, that will certainly help our company from having to make expected payroll cuts over the next three weeks.
You look like a “thinker” to me, even with the obvious “bronzing.”
The hospital where my daughter works does not test its employees unless they have WuFlu symptoms.