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Having an antibody bind the virus is good, but not enough. The antibody needs to end up activating the immune system. Sometimes antibodies binding to the virus

Having an antibody bind the virus is good, but not enough. The antibody needs to end up activating the immune system. Sometimes antibodies binding to the virus can sometimes enhance the infection: Potential Mechanims of Age Related Severity Of COVID-19 Infection: Implications for Development of Vaccines, Convalescent Serum, and Antibody Therapies https://www.researchgate.net/publication/340005309_Potential_Mechanisms_of_Age_Related_Severity_of_COVID-19_Infection_Implications_for_Vaccine_Development_and_Convalescent_Serum_Therapy https://www.researchgate.net/publication/340005309_Potential... The back fo the antibody (Fc region) to COVID needs to be conjugated with an activating factor.

AstralStorm 7y ago
It's the light chain that binds, you can modify heavy chain to do what you need and said. This is what's done when humanizing antibodies too. The extra infection potential is when the virus or bacteria can survive or thrive inside macrophages or monocytes, which react to opsonized particles, such as with antibodies. You can make IgA or IgM instead to prevent this mechanism. They work by polymerization to bind whatever they attach to. Former is typically not activating the rest of immune system, while IgM would activate everything strongly perhaps inducing your own production.
- freetime2 7y ago
  Wow is the least comprehensible (to me) comment I’ve ever seen on HN. Well played!
  - AstralStorm 7y ago
    I'll try to explain below. Monoclonal antibodies, or mAb are made usually by fusing a right B cell or splicing a gene sequence for the right light chains (V, D) into a leukemic cancer cell line producing a so called hybridoma. Those cells are damaged in such a way as to produce tons of antibodies and are immortal. By using a different starter cell line you can get different antibody classes. Also by providing a different interleukin stimulus to the cells. Typically IgG is made because it's easiest, but there are options. See: https://www.sciencedirect.com/science/article/abs/pii/S0022175915001246?via%3Dihub https://www.sciencedirect.com/science/article/abs/pii/S00221... Here's a helpful blog post: https://www.tebu-bio.com/blog/2018/11/13/monoclonal-antibodies-all-you-need-to-know-about-antibody-generation/ https://www.tebu-bio.com/blog/2018/11/13/monoclonal-antibodi...
    - freetime2 7y ago
      Fascinating... thanks for the additional info!
  - DoofusOfDeath 7y ago
    To be fair, the first two stanzas in that post are the most poetic I've ever read on HN.
christkv 7y ago
From my understanding when an antibody attaches to a virus it causes a signal for T-cells to eat the and destroy the virus. So the antibody would be effective in getting the body to destroy any virus found. However I don't think it would create any sort of immune memory which is what a vaccine or recovering from the illness by yourself would do. That said it would be fantastic in that it could provide some immunity protection for a while why the antibodies are active in your body allowing health care workers to be safer. Might also be very helpful in creating firewalls in institutions like old folks homes or hospitals.
- dmix 7y ago
  Are there some examples of antibodies like this being employed successfully like that? I find it fascinating how the body is able to adapt to new entrants and the immune system figures out how to uniquely bind to the virus - but seemingly based on the article only when it changes into an active infection mode and exposes a certain part. Potentially ignoring it unless it’s an active threat to the body.
  - AstralStorm 7y ago
    Yes, there have been some trials in avian flu at least, and a few attempts in original SARS and MERS, with success. The problem here is the mediocre quality of evidence. Mostly limited sizes, but also lacking randomization. Also rabies, tetanus and hepatitis B and C sera are available. Those have high quality evidence for working.
- koheripbal 7y ago
  This is exactly the problem. It would only work in the short term - but would not provide any immunity. It might not even eliminate the virus - so once you stop the antibody treatment - the patient might relapse. Still better than nothing and in extreme situations, it would give your body more time to produce an adaptive response.

AstralStorm 7y ago

It's the light chain that binds, you can modify heavy chain to do what you need and said. This is what's done when humanizing antibodies too. The extra infection potential is when the virus or bacteria can survive or thrive inside macrophages or monocytes, which react to opsonized particles, such as with antibodies. You can make IgA or IgM instead to prevent this mechanism. They work by polymerization to bind whatever they attach to. Former is typically not activating the rest of immune system, while IgM would activate everything strongly perhaps inducing your own production.

freetime2 7y ago
Wow is the least comprehensible (to me) comment I’ve ever seen on HN. Well played!
- AstralStorm 7y ago
  I'll try to explain below. Monoclonal antibodies, or mAb are made usually by fusing a right B cell or splicing a gene sequence for the right light chains (V, D) into a leukemic cancer cell line producing a so called hybridoma. Those cells are damaged in such a way as to produce tons of antibodies and are immortal. By using a different starter cell line you can get different antibody classes. Also by providing a different interleukin stimulus to the cells. Typically IgG is made because it's easiest, but there are options. See: https://www.sciencedirect.com/science/article/abs/pii/S0022175915001246?via%3Dihub https://www.sciencedirect.com/science/article/abs/pii/S00221... Here's a helpful blog post: https://www.tebu-bio.com/blog/2018/11/13/monoclonal-antibodies-all-you-need-to-know-about-antibody-generation/ https://www.tebu-bio.com/blog/2018/11/13/monoclonal-antibodi...
  - freetime2 7y ago
    Fascinating... thanks for the additional info!
- DoofusOfDeath 7y ago
  To be fair, the first two stanzas in that post are the most poetic I've ever read on HN.

christkv 7y ago

From my understanding when an antibody attaches to a virus it causes a signal for T-cells to eat the and destroy the virus. So the antibody would be effective in getting the body to destroy any virus found. However I don't think it would create any sort of immune memory which is what a vaccine or recovering from the illness by yourself would do. That said it would be fantastic in that it could provide some immunity protection for a while why the antibodies are active in your body allowing health care workers to be safer. Might also be very helpful in creating firewalls in institutions like old folks homes or hospitals.

dmix 7y ago
Are there some examples of antibodies like this being employed successfully like that? I find it fascinating how the body is able to adapt to new entrants and the immune system figures out how to uniquely bind to the virus - but seemingly based on the article only when it changes into an active infection mode and exposes a certain part. Potentially ignoring it unless it’s an active threat to the body.
- AstralStorm 7y ago
  Yes, there have been some trials in avian flu at least, and a few attempts in original SARS and MERS, with success. The problem here is the mediocre quality of evidence. Mostly limited sizes, but also lacking randomization. Also rabies, tetanus and hepatitis B and C sera are available. Those have high quality evidence for working.
koheripbal 7y ago
This is exactly the problem. It would only work in the short term - but would not provide any immunity. It might not even eliminate the virus - so once you stop the antibody treatment - the patient might relapse. Still better than nothing and in extreme situations, it would give your body more time to produce an adaptive response.