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Covid-19’s stop-gap solution until vaccines and antivirals are ready

globalhealthnow.org

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Re: Covid-19’s stop-gap solution until vaccines and antivirals are ready

#11

Post by Retric »

booi wrote: post #8
Retric wrote: post #6

Earlier quoted context omitted.

You’re injecting blood products from another person so catching some other deadly disease is a real risk. Plasma is tested for AIDS and several other diseases, but prions for example are much harder to detect. Further, when you consider the risk of someone messing up on the supply side that opens up a host of issues.

That’s why there is comprehensive screening of donated blood which has essentially eliminated pathogen transfer and it’s used en masse everyday.

As you say pathogen transfer and other complications like GvHD are rare, but that’s also in normal situations. In a pandemic things change. This example is using plasma from China which is very much outside of normal channels.

Further, in a pandemic when staff are overworked and possibly sick, mistakes are going to increase. Viable in a life threading situation, less so: “for prevention of infection for people who are being exposed.”

Re: Covid-19’s stop-gap solution until vaccines and antivirals are ready

#12

Post by Retric »

ghufran_syed wrote: post #10
Retric wrote: post #6

Earlier quoted context omitted.

You’re injecting blood products from another person so catching some other deadly disease is a real risk. Plasma is tested for AIDS and several other diseases, but prions for example are much harder to detect. Further, when you consider the risk of someone messing up on the supply side that opens up a host of issues.

This paper has a good overview, they say the rate of adverse events is around 1/1700. So if it reduces your risk of death from respiratory failure in the next week by almost any positive amount, it's worth doing. This is only going to be used in hospitalized patients who are already developing respiratory failure (low blood oxygen levels), not in random people off the street with a cough. https://www.ncbi.nlm.nih.gov…

I agree with you, but here is a direct quote from the article:

“it can be used for prevention of infection for people who are being exposed or it could be used for therapy for those who are sick.” This is not something to generally be handing out to people after simple exposure.

Re: Covid-19’s stop-gap solution until vaccines and antivirals are ready

#13

Post by rootusrootus »

ghufran_syed wrote: post #7
fernly wrote: post #2

Could somebody with medical knowledge speak to the lifetime of exogenous antibodies in another person's blood? And, does their presence in any way "train" the host immune system to make more? Or is the benefit solely from the introduced antibodies?

The half-life of exogenous antibodies is around one month: https://pubmed.ncbi.nlm.nih.gov/3183495/ The benefit is solely from the antibodies attacking and reducing the level of virus in the body, it does NOT induce an immune response from the body (though that will happen anyway as the body mounts it's normal immune response to the virus)

So it does not interfere with the body's own immune response, and in the end the patient should be immune in their own right (for however long that lasts)?

Almost sounds too good to be true. I wonder what the real downside risks are.

Re: Covid-19’s stop-gap solution until vaccines and antivirals are ready

#14

Post by rsfern »

ghufran_syed wrote: post #7
fernly wrote: post #2

Could somebody with medical knowledge speak to the lifetime of exogenous antibodies in another person's blood? And, does their presence in any way "train" the host immune system to make more? Or is the benefit solely from the introduced antibodies?

The half-life of exogenous antibodies is around one month: https://pubmed.ncbi.nlm.nih.gov/3183495/ The benefit is solely from the antibodies attacking and reducing the level of virus in the body, it does NOT induce an immune response from the body (though that will happen anyway as the body mounts it's normal immune response to the virus)

Interesting — I wonder if that’s the reason the article says that one recovered persons plasma could treat just two additional patients? It’s not clear how much plasma would be needed for the treatment

Re: Covid-19’s stop-gap solution until vaccines and antivirals are ready

#15

Post by rsfern »

Retric wrote: post #3

While viable and potentially lifesaving, the risks associated with this type of treatment are significant and should not be downplayed. Edit: This is the line I am objecting to: “ it can be used for prevention of infection for people who are being exposed or it could be used for therapy for those who are sick.” This is not something to generally be handing out to people after simple exposure. For one thing the benifi…

The JHU team is waiting on FDA approval for a clinical trial...

Re: Covid-19’s stop-gap solution until vaccines and antivirals are ready

#16

Post by koolba »

>> You're making sure that there are antibodies in there and that they would be effective?

> Exactly. Exactly—that we have a potent unit. We think that one person can treat two people.

Does this work in an ongoing chain? For example if person A’s plasma is used to treat B, can we take from B and treat C as well?

Or does the quality of the anti-bodies depend purely on the immune system of the hose?

Re: Covid-19’s stop-gap solution until vaccines and antivirals are ready

#17

Post by rsfern »

Formal writeup here: https://www.jci.org/articles/view/138003

Edit: lots of interesting details. a couple takeaways:

1. “Depending on the antibody amount and composition, the protection conferred by the transferred immunoglobulin can last from weeks to months.”

2. One of the proposed deployments is to protect frontline health care workers from infection (and remove their need to quarantine) until a vaccine can be developed

3. This treatment was apparently used for quite a few other outbreaks, including the 1918 flu epidemic, MERS, and there is a report of it being used against the novel Coronavirus in China

Re: Covid-19’s stop-gap solution until vaccines and antivirals are ready

#18

Post by rpedela »

Retric wrote: post #12
ghufran_syed wrote: post #10

Earlier quoted context omitted.

This paper has a good overview, they say the rate of adverse events is around 1/1700. So if it reduces your risk of death from respiratory failure in the next week by almost any positive amount, it's worth doing. This is only going to be used in hospitalized patients who are already developing respiratory failure (low blood oxygen levels), not in random people off the street with a cough. https://www.ncbi.nlm.nih.gov…

I agree with you, but here is a direct quote from the article: “ it can be used for prevention of infection for people who are being exposed or it could be used for therapy for those who are sick.” This is not something to generally be handing out to people after simple exposure.

Researchers always talk about what could be but not necessarily what should be. Don't worry too much, in practice what you suggest will most likely happen.

Re: Covid-19’s stop-gap solution until vaccines and antivirals are ready

#19

Post by refurb »

Retric wrote: post #6
scotth wrote: post #4

Earlier quoted context omitted.

For example?

You’re injecting blood products from another person so catching some other deadly disease is a real risk. Plasma is tested for AIDS and several other diseases, but prions for example are much harder to detect. Further, when you consider the risk of someone messing up on the supply side that opens up a host of issues.

Based on the HIV epidemic back in the 1980s, techniques have been developed to inactivate any pathogen in donated plasma. They can use detergents or heat.

Could something slip by? Sure, but it’s a pretty robust system.

Re: Covid-19’s stop-gap solution until vaccines and antivirals are ready

#20

Post by maxerickson »

rootusrootus wrote: post #13
ghufran_syed wrote: post #7

Earlier quoted context omitted.

The half-life of exogenous antibodies is around one month: https://pubmed.ncbi.nlm.nih.gov/3183495/ The benefit is solely from the antibodies attacking and reducing the level of virus in the body, it does NOT induce an immune response from the body (though that will happen anyway as the body mounts it's normal immune response to the virus)

So it does not interfere with the body's own immune response, and in the end the patient should be immune in their own right (for however long that lasts)? Almost sounds too good to be true. I wonder what the real downside risks are.

We used to use horse serum to treat infections. Inject the horse with the disease and then filter the antibodies out of the blood.

https://en.wikipedia.org/wiki/Antiserum

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