Author Topic: Dropping Antibody Levels  (Read 16424 times)

Offline avromie7

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Re: Dropping Antibody Levels
« Reply #225 on: October 22, 2020, 12:51:49 PM »
Yes, you're 100% right.   :D 
I just meant there's a real, though very small, chance that an Ab+ person will get sick or get others sick. 

Me: we're 95% certain they're not carrying the virus.
Avromie7: we're 95% certain they can't carry the virus.

For Israel, they just want to know if that person is carrying the virus on that flight, so I'm not sure what you're adding,  @avromie7 .
The way you wrote it, it says there is a 5% chance they are infected which is inaccurate. I changed it to say there is a 5% chance they can be infected which means compared to everyone else, they are 20x less likely to be infected.
I wonder what people who type "u" instead of "you" do with all their free time.

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Re: Dropping Antibody Levels
« Reply #226 on: October 22, 2020, 12:57:40 PM »
@biobook or anyone. I know the title says "dropping antibody levels" but here we have a clear case of higher levels 2 weeks later (and about 7 months from presumed COVID-19 infection). Are there any other similar DP? Is it possible that the levels just fluctuate? What can influence them?
I don't know the answer, but in general, biological variables fluctuate, some minute to minute, some hourly, some over the course of the day, some over weeks. 

A personal example: A few years ago, my doctor wanted to do a routine blood test for cholesterol.  A few days later, I got a call from his office saying my results were over 300, so high that I should return right away for another test.  I called a doctor-friend, and his first question was "Were you dehydrated when they took blood?"  Was he looking over my shoulder?  Of course, I was!  I was supposed to be fasting, so hadn't eaten or drunk all morning, and of course I was late, so I ran to the office, and it was in the summer, so a sweating hot day, and the waiting room was packed, so I had a long wait, and the first thing I did when I left was to get a drink.  He explained that tests of anything in the blood are reported as mg of something per ml of watery blood, so if you're dehydrated, the same amount of cholesterol is now dissolved in a smaller amount of watery blood, and so the result can be artificially high.  Sure enough, a few days later, I drank water normally before the test (and walked over there slowly!) and my cholesterol was boringly normal.

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Re: Dropping Antibody Levels
« Reply #227 on: October 22, 2020, 12:59:29 PM »
The way you wrote it, it says there is a 5% chance they are infected which is inaccurate. I changed it to say there is a 5% chance they can be infected which means compared to everyone else, they are 20x less likely to be infected.
Oh, okay. :)

Offline ExGingi

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Re: Dropping Antibody Levels
« Reply #228 on: October 22, 2020, 01:11:03 PM »
A positive antibody test implies that someone PROBABLY has been exposed to coronavirus, and PROBABLY is immune, and so is PROBABLY not carrying live virus now.  There's a lot of uncertainty there, but based on our knowledge of other coronaviruses, let's say we're 95% certain they're not carrying the virus.  So a group of antibody-positive travelers is much less likely to import the virus than a random group of people coming from NY/NJ.  Some infected people probably WILL enter, but hopefully very few.  If Israel is trying to ramp up travel, it makes sense to begin by allowing this group in first, and seeing how it goes. (Actually, they rescinded permission for this yesterday, I think, not sure why.)

This is the frustrating part, causing serious mental anguish.

One would think that it would make tremendous sense to allow entry to antibody+ individuals, especially since there are so many of those (that never had a positive PCR test, because they had COVID-19 without severe symptoms when PCR tests were being rationed) within a demographic that is likely to have many ready and willing to travel and spend money in Israel.

BUT... nothing (there) is done with any logic.

The rescinding of the authorization to exit mandatory quarantine based on antibody testing was purely due to technicalities and bureaucratic reasons. They approved it, but didn't manage to set up the logistics of how it would be done (and the obvious wrangling as to who gets the funds).
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Offline ExGingi

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Re: Dropping Antibody Levels
« Reply #229 on: October 22, 2020, 01:13:05 PM »
I don't know the answer, but in general, biological variables fluctuate, some minute to minute, some hourly, some over the course of the day, some over weeks. 

A personal example: A few years ago, my doctor wanted to do a routine blood test for cholesterol.  A few days later, I got a call from his office saying my results were over 300, so high that I should return right away for another test.  I called a doctor-friend, and his first question was "Were you dehydrated when they took blood?"  Was he looking over my shoulder?  Of course, I was!  I was supposed to be fasting, so hadn't eaten or drunk all morning, and of course I was late, so I ran to the office, and it was in the summer, so a sweating hot day, and the waiting room was packed, so I had a long wait, and the first thing I did when I left was to get a drink.  He explained that tests of anything in the blood are reported as mg of something per ml of watery blood, so if you're dehydrated, the same amount of cholesterol is now dissolved in a smaller amount of watery blood, and so the result can be artificially high.  Sure enough, a few days later, I drank water normally before the test (and walked over there slowly!) and my cholesterol was boringly normal.

I could have told you that (without knowing any science thereof). I usually recommend to my clients to fast prior to giving blood for an insurance exam, and then drink as much water as they humanly can starting about an hour or two prior to the exam. Usually comes back with great results.
I've been waiting over 5 years with bated breath for someone to say that!
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Online skyguy918

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Re: Dropping Antibody Levels
« Reply #230 on: October 22, 2020, 01:56:13 PM »
Okay, so here's a different assumption  :)  When the doctor said "a little over immunity level" he probably meant "a little over antibody threshold level", that is, a little over the number that is used to conclude that the antibody test is positive.  Nobody knows yet what level of antibody will provide the immunity needed to avoid a second infection. 
I feel like you're imposing your own knowledge around what the scientific/medical consensus is on the wider world, and it's starting to get a little grating. Consensus (which again, doesn't really exist on many questions surrounding COVID) is not universal agreement. I already mentioned the fact that this doctor told me after my positive rapid test that I and my kids need to quarantine, but that my wife's positive antibody test from a week prior (the one where he told her at the time it's above immunity level but not by much) was sufficient to allow her not to quarantine. I don't believe any government guidelines would agree with that, nor are most doctors giving this advice. all medical professionals. And to be honest, my wife generally quarantined, except for maybe one very quick run to the supermarket (masked up).

As far as being a little over immunity level vs a little over positive result level - that's just not the case. When my whole family tested after Sukkos (at an NYC H&H location), her result was ~50. The threshold indicating a positive result is 1.00 (two of my kids were below that mark). The other 3 positives in the family were much higher than 50.
But decisions we make for groups of people - public health - is not always the same as decisions made for individual health. 

If 95% of Ab+ people are immune today (and I totally made up this number), it still means that 5% of Ab+ people are susceptible to infection/reinfection/transmitting the virus to others.  And that 5% will increase over time as immunity weakens. 

As an individual, my goal is to prevent illness to myself and others. The antibody test doesn't give a yes/no answer to immunity.  If I'm Ab+, I wouldn't say "Now, I'm immune, I can spend time with my great grandmother."  Rather, "Now there's a 95% chance I'm immune, and only a 5% chance that if I spend time with my great grandmother, I'll infect her and cause her death."  We need to keep that (still unknown) probability in mind when we make our decisions.
I'm not sure what any of this has to do with my question. I noted that immunity would not be changing my behavior,
...Realistically it's not changing my behavior, but I am curious.
So to be honest, it's a little insulting for you to respond with a scenario about using immunity to justify changing behaviors.

Online biobook

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Re: Dropping Antibody Levels
« Reply #231 on: October 22, 2020, 08:07:14 PM »
I'm not sure what any of this has to do with my question.

I noted that immunity would not be changing my behavior,So to be honest, it's a little insulting for you to respond with a scenario about using immunity to justify changing behaviors.

My sincere apologies.  I make an effort to not insult anyone here, and I'm sorry if you were offended by what I wrote.  I did read your comment that you wouldn't change your behavior based on immunity, and I did think "kol hakavod!" and should have written that.  I wasn't thinking specifically of you when I wrote my post.  I'm aware that responses to one person are often read by others here, and so I tried to phrase my post in a way that would make it understandable and meaningful for DDFers in general.  (And others did read it, and - correctly - noted where my explanation was defective.) ::)

I already mentioned the fact that this doctor .... told her at the time it's above immunity level but not by much) was sufficient to allow her not to quarantine...

I agree that an individual doctor might give a patient advice that doesn't exactly comply with government guidelines.  I'm not disagreeing with his decision that quarantine is unnecessary.  It's just the use of the words "immunity level" which seem puzzling, since it was antibodies that were measured, not immunity.  But I see that the first two ways I came up with to resolve this weren't right, so perhaps the only way to know what he meant by it is to ask him.

I feel like you're imposing your own knowledge around what the scientific/medical consensus is on the wider world, and it's starting to get a little grating.
Could you clarify this?  I take care not to insult, but haven't been paying attention to whether I grate.  I get that you think I'm annoying, but I don't know what you think I should stop doing.

Offline how

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Re: Dropping Antibody Levels
« Reply #232 on: October 23, 2020, 02:49:26 PM »
DW just got her test results from Hadassah Medical in EY. Her IgG number shows about 2x what her most recent test taken in the US showed. (Same scale. Over 15.0 considered positive).
I assume itís possible that a recent exposure mightíve caused the increase in antibodies

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Re: Dropping Antibody Levels
« Reply #233 on: October 23, 2020, 04:46:07 PM »
@skyguy918  Could you do me a favor and return to this thread?  I'm trying to improve my writing skills, so your feedback may be helpful, but I don't understand your comments.  I'd appreciate if you could explain. TIA.

Offline ExGingi

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Re: Dropping Antibody Levels
« Reply #234 on: October 23, 2020, 04:56:15 PM »
I assume itís possible that a recent exposure mightíve caused the increase in antibodies

There was no known exposure.
I've been waiting over 5 years with bated breath for someone to say that!
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Offline drosenberg88429

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Re: Dropping Antibody Levels
« Reply #235 on: October 23, 2020, 05:21:06 PM »
There was no known exposure.

If she lived in Brooklyn or a chareidi area in Israel, there was almost guaranteed exposure.

Offline ExGingi

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Re: Dropping Antibody Levels
« Reply #236 on: October 23, 2020, 05:28:24 PM »
If she lived in Brooklyn or a chareidi area in Israel, there was almost guaranteed exposure.

Well, there was definitely exposure around Purim. But no known or likely exposure between the recent antibody test taken in Brooklyn and the one taken in EY.

I really don't know which universe you're living in, thinking that Brooklyn (Crown Heights specifically) would be guaranteed exposure since Shavuos.
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Online biobook

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Re: Dropping Antibody Levels
« Reply #237 on: October 25, 2020, 07:26:57 PM »
@biobook or anyone. I know the title says "dropping antibody levels" but here we have a clear case of higher levels 2 weeks later (and about 7 months from presumed COVID-19 infection). Are there any other similar DP? Is it possible that the levels just fluctuate? What can influence them?
Here's a partial answer. Quebec researchers measured antibody levels in recovered covid patient who donated convalescent plasma repeatedly. Each line on the graph is another person.  Although antibodies decreased in general over this time period, you can see it fluctuates, and sometimes one measurement is actually higher than the previous one in that person.

https://ashpublications.org/blood/article/doi/10.1182/blood.2020008367/463996/Waning-of-SARS-CoV-2-RBD-antibodies-in
The authors ask whether the repeated donations might actually be responsible for the decline in antibodies. When @Dan suggested this a month ago, I answered that I thought it unlikely based on theoretical issues. The authors apparently did consider it possible, but also concluded that it's unlikely, based on their results here. Their reasoning was that if donating antibodies depleted the supply, then antibody levels should drop more rapidly in those who donated more times, but there was no such correlation.

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Re: Dropping Antibody Levels
« Reply #238 on: October 27, 2020, 08:29:49 PM »
Why You Shouldnít Worry About Studies Showing Waning Coronavirus Antibodies
https://www.nytimes.com/2020/10/27/health/coronavirus-antibodies-studies.html

Offline ExGingi

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I've been waiting over 5 years with bated breath for someone to say that!
-- Dan