Author Topic: Dropping Antibody Levels  (Read 29169 times)

Offline Traveler718

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Re: Dropping Antibody Levels
« Reply #320 on: March 02, 2021, 02:58:49 PM »
In Israel they're valid for 6 months.

Wow, that's very helpful - source? Is there any US guidance on this topic whether the same 6 months or a different period of time? And is it 6 months only from the original post-COVID result, or even subaequent retests reset the clock for an additional 6 months?

Offline biobook

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Re: Dropping Antibody Levels
« Reply #321 on: March 03, 2021, 02:42:07 AM »
If someone tests positive for antibodies, after how much time is it recommended to retest? We are making a family simcha soon and are requiring those coming who haven't been fully vaccinated and don't have recent antibodies to take a PCR test before coming. The issue is where to draw the cutoff line.

It's clear that the person who tested positive for antibodies 3 weeks ago is fine, but what about someone who was tested on Chanuka or Sukkos or last summer? And does it make a difference whether they were actually symptomatic and tested positive for COVID? I tried Google but couldn't fine any clear guidance on this topic. @biobook
Did you add @biobook in the Edit?  I just came across this post, but hadn't gotten an email ping, so wondering if it happens when editing, or if it's something with my email.

When I looked into this - I think it was a couple months ago - the guidance (CDC and others) was to NOT base decisions about social behavior on antibody level because a) there was no known level of antibody about which we could say above this threshold, you're immune, and b) even if antibodies were low, a person might still be immune due to having memory B and T cells. 

But as we get more data, it is clear that most people are not getting reinfected so far, and so the recommendation is to consider TIME since infection, rather than antibody level, if you're trying to get a sense of immunity.  One study found that immunity for 95% of people studied lasts as long as 8 months, based on detailed study of antibodies as well as B cells and T cells. 

This was officially published a few weeks ago in Science: Immunological memory to SARS-CoV-2 assessed for up to 8 months after infection https://science.sciencemag.org/content/371/6529/eabf4063 but more informally in the news in November:  https://www.nytimes.com/2020/11/17/health/coronavirus-immunity.html 

So this seems to imply that immunity lasts at least 6-8 months after the infection, not 6-8 months after whenever the antibody test happened to be given.  So, in theory, there would be no need for an antibody test, if someone had a confirmed case of covid, they've probably got good immunity for the next 6 months.

On the other hand, there have been cases of reinfection, and no studies that I've seen on what antibody levels were in those who were reinfected.  And, in general, it's been found that those who had less severe or asymptomatic infections have lower antibody levels, though I don't know if they've looked at their T and B memory cells.

The PCR test also seems problematic.  Someone can test negative in the early stage of infection, and then be positive a couple days later when they're at your simcha.  Or they can pick up the infection during all the interactions that occur while traveling. 

And add to that all the uncertainty about the new variants, and whether the antibodies will be effective against them.

What Dr Fauci and Dr Wallensky have been saying is that now is not a good time for travel and social get togethers with people who aren't part of your current living group, especially considering how close we seem to be to widespread vaccination. I think that's why you haven't been able to find any clear guidance on this topic, because the guidance is that we just don't know yet if it's safe. 

If it were my family, I'd be telling them that we're making such an extra special party them and we realize now that it won't be ready before August, so we'll zoom for now, and invite you all to visit in the summer.  But I'm sure it's obvious by now that I'm on the low-risk end of the spectrum.

Offline AsherO

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Re: Dropping Antibody Levels
« Reply #322 on: March 03, 2021, 08:42:37 AM »
Did you add @biobook in the Edit?  I just came across this post, but hadn't gotten an email ping, so wondering if it happens when editing, or if it's something with my email.

When I looked into this - I think it was a couple months ago - the guidance (CDC and others) was to NOT base decisions about social behavior on antibody level because a) there was no known level of antibody about which we could say above this threshold, you're immune, and b) even if antibodies were low, a person might still be immune due to having memory B and T cells. 

But as we get more data, it is clear that most people are not getting reinfected so far, and so the recommendation is to consider TIME since infection, rather than antibody level, if you're trying to get a sense of immunity.  One study found that immunity for 95% of people studied lasts as long as 8 months, based on detailed study of antibodies as well as B cells and T cells. 

This was officially published a few weeks ago in Science: Immunological memory to SARS-CoV-2 assessed for up to 8 months after infection https://science.sciencemag.org/content/371/6529/eabf4063 but more informally in the news in November:  https://www.nytimes.com/2020/11/17/health/coronavirus-immunity.html 

So this seems to imply that immunity lasts at least 6-8 months after the infection, not 6-8 months after whenever the antibody test happened to be given.  So, in theory, there would be no need for an antibody test, if someone had a confirmed case of covid, they've probably got good immunity for the next 6 months.

On the other hand, there have been cases of reinfection, and no studies that I've seen on what antibody levels were in those who were reinfected.  And, in general, it's been found that those who had less severe or asymptomatic infections have lower antibody levels, though I don't know if they've looked at their T and B memory cells.

The PCR test also seems problematic.  Someone can test negative in the early stage of infection, and then be positive a couple days later when they're at your simcha.  Or they can pick up the infection during all the interactions that occur while traveling. 

And add to that all the uncertainty about the new variants, and whether the antibodies will be effective against them.

What Dr Fauci and Dr Wallensky have been saying is that now is not a good time for travel and social get togethers with people who aren't part of your current living group, especially considering how close we seem to be to widespread vaccination. I think that's why you haven't been able to find any clear guidance on this topic, because the guidance is that we just don't know yet if it's safe. 

If it were my family, I'd be telling them that we're making such an extra special party them and we realize now that it won't be ready before August, so we'll zoom for now, and invite you all to visit in the summer.  But I'm sure it's obvious by now that I'm on the low-risk end of the spectrum.

When you cite numbers like 95% after 6-8 months, and when we see similar numbers for fully vaccinated (mRNA) people, we need to consider the following:

These numbers are accurate in aggregate, but for an individual, or especially multiple individuals, they might (as a fluke) be an exception and have waning antibodies or get infected post-vaccination. Having 50-100 such people at a simcha today (with new confirmed infections in our communities every day) means there’s a real (albeit small, but real) possibility that ch”v a non-immune vulnerable/at-risk family member at this simcha could get infected.

@biobook makes a valid case for the fact that you don’t need antibody testing, but if you’re using that as a proxy and/or to mitigate perceived risks (while not foolproof), then the longer it’s been since someone was infected and/or has a confirmed antibody test, the greater value you’ll have from retesting.

Offline ExGingi

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Re: Dropping Antibody Levels
« Reply #323 on: March 03, 2021, 09:32:48 AM »
You just love blood tests don’t you

Yup. I think I'll try MBM antibody tests.
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Offline etech0

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Re: Dropping Antibody Levels
« Reply #324 on: March 03, 2021, 09:40:04 AM »
Yup. I think I'll try MBM antibody tests.
multiple bloodtest method, sounds good
Workflowy. You won't know what you're missing until you try it.

Offline ExGingi

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Re: Dropping Antibody Levels
« Reply #325 on: March 03, 2021, 11:29:47 AM »
multiple bloodtest method, sounds good

What's the bloodtest equivalent term for App-O-Rama?
I've been waiting over 5 years with bated breath for someone to say that!
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Offline gozalim

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Re: Dropping Antibody Levels
« Reply #326 on: March 03, 2021, 05:18:28 PM »
What's the bloodtest equivalent term for App-O-Rama?
shootout?

Offline bingit

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Re: Dropping Antibody Levels
« Reply #327 on: March 03, 2021, 10:15:33 PM »
I just took another antibody test in Lakewood by Friendly urgent care using BioRefrence lab and it came back positive with the number 71.8, is that considered lots of antibodies??

Offline Dan

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Re: Dropping Antibody Levels
« Reply #328 on: March 03, 2021, 10:20:15 PM »
I just took another antibody test in Lakewood by Friendly urgent care using BioRefrence lab and it came back positive with the number 71.8, is that considered lots of antibodies??
Take the Roche test at Labcorp if you want to compare apples to apples from the most reliable Antibody test.
Save your time, I don't answer PM. Post it in the forum and a dedicated DDF'er will get back to you as soon as possible.

Offline ExGingi

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Re: Dropping Antibody Levels
« Reply #329 on: March 04, 2021, 10:47:49 AM »
@AsherO do you know which test NYC Health+Hospitals use?
I've been waiting over 5 years with bated breath for someone to say that!
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Offline AsherO

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Re: Dropping Antibody Levels
« Reply #330 on: March 04, 2021, 01:07:21 PM »
@AsherO do you know which test NYC Health+Hospitals use?

@ExGingi Here you go:

NYC Health & Hospitals was using a quantitative Roche antibody test as far back as Sukkos at least, but it doesn't appear to be the same exact test. The cutoff was .99, not .81, and they didn't provide a total range.

https://www.fda.gov/media/137603/download

They were using the same in December as well IME. Here’s the patient fact sheet:
https://www.fda.gov/media/137604/download

Tried to get another one recently but they told me they only test for antibodies once every 3 months.

Offline ExGingi

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Re: Dropping Antibody Levels
« Reply #331 on: March 04, 2021, 01:27:02 PM »
@ExGingi Here you go:

They were using the same in December as well IME. Here’s the patient fact sheet:
https://www.fda.gov/media/137604/download

Tried to get another one recently but they told me they only test for antibodies once every 3 months.

So no MBM for antibody testing?
I've been waiting over 5 years with bated breath for someone to say that!
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Offline AsherO

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Re: Dropping Antibody Levels
« Reply #332 on: March 04, 2021, 01:34:53 PM »
So no MBM for antibody testing?

I guess not? Maybe if you can convince them you’re someone else then you can test under another name?

Offline Dan

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Re: Dropping Antibody Levels
« Reply #333 on: March 04, 2021, 01:44:57 PM »
So no MBM for antibody testing?
Can go as often as you want to Lapcorp. Insurance pays in full.
Save your time, I don't answer PM. Post it in the forum and a dedicated DDF'er will get back to you as soon as possible.

Offline AsherO

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Re: Dropping Antibody Levels
« Reply #334 on: March 04, 2021, 01:48:25 PM »
Can go as often as you want to Lapcorp. Insurance pays in full.

All insurances? I called my carrier in the summer and was advised they “only cover one COVID test”, they phone rep couldn’t provide any further guidance whether it’s one test per exposure/symptoms incident, per time period, or something else.

Offline ExGingi

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Re: Dropping Antibody Levels
« Reply #335 on: March 04, 2021, 03:45:48 PM »
Can go as often as you want to Lapcorp. Insurance pays in full.

I highly doubt it.
I've been waiting over 5 years with bated breath for someone to say that!
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Re: Dropping Antibody Levels
« Reply #336 on: March 04, 2021, 03:49:46 PM »
I highly doubt it.
I've done 4 without issue.
Save your time, I don't answer PM. Post it in the forum and a dedicated DDF'er will get back to you as soon as possible.

Offline AsherO

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Re: Dropping Antibody Levels
« Reply #337 on: March 04, 2021, 03:52:38 PM »
I've done 4 without issue.

You might have better insurance than many here.

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Re: Dropping Antibody Levels
« Reply #338 on: March 04, 2021, 04:10:15 PM »
I've done 4 without issue.

Things can and do slip through. But from an insurance perspective, if there's no medical reason for it, it really shouldn't be covered.
I've been waiting over 5 years with bated breath for someone to say that!
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Offline Ergel

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Re: Dropping Antibody Levels
« Reply #339 on: March 04, 2021, 04:20:22 PM »
I've done 4 without issue.
::) Gosh, can someone please find the relevant quote
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