Why is it that children rarely get seriously ill

[signet, LPN]

It seems to be the case that children and young adults (under 20) aren't getting seriously ill from Covid19. Why? If we could find out, maybe there is a way to give this protection to adults. Has anyone tried taking a blood donation from a high school age person and giving it to an older person to see if there would be any protection imparted? This seems like a simple idea that wouldn't cause harm to either person. If there's something in the blood protecting younger people that we have not yet discovered, wouldn't this be prudent? I'm talking about a standard blood donation, not convalescent plasma. Does anyone know if this has been tried?

[toomuchbaloney]

https://www.nejm.org/doi/full/10.1056/NEJMc2005073

https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(20)30152-1/fulltext

There's so much to learn about this virus...

[HandsOffMySteth]

It could be that children and young adults have a bigger thymus than older adults. It could have something to do with the state of development in their immune system. There are a lot of variables to research but I think they will focus on other things. There are also adults who are asymptomatic as well. There is well known information on the cytokine storm syndrome that causes an overreaction by the immune system caused by introduction of an superantigen.

[adventure_rn, MSN, NP]

My understanding is that it has to do with kids' more immature, naive immune systems.

In adults with COVID-19, there's the initial respiratory assault, followed by a systemic immune response which harms the rest of your organ systems (heart, kidneys, etc.) and causes multi-system organ dysfunction. The sequelae remind me of a cytokine storm.

https://www.nature.com/articles/d41586-020-01056-7

https://www.newscientist.com/term/cytokine-storm/

Very young kids have relatively immature immune systems (given their limited exposures), and so they may not mount such a severe immune response to the virus.

It reminds me a bit of food allergies--the initial cause (I.e. peanuts) isn't necessarily dangerous, but the immune response itself can be fatal. In the same way, the respiratory effects of COVID might not be as dangerous as the immune response that it initiates. Little babies don't have food allergies because their immune systems are very immature; similarly, even if they catch COVID, they don't appear to mount the same catastrophic, harmful immune response. That's part of the reason why scientists are studying immunosuppresent drugs (steroids, chloroquine, and hydroxychloroquine) as treatments for COVID.

Severe COVID cases also seem to result in coagulopathy and uncontrolled clotting. This is just conjecture (I don't have any evidence to support it), but it would make sense to me that kids are a lower risk for clotting and coagulopathy simply because their CV systems are younger and healthier, with less plaque in their blood vessels overall.

Regardless, I don't think that giving older people blood from younger people would be helpful. Perhaps if we can get the blood of people who have been infected and have subsequently recovered, then we could spin it down to isolate their antibodies and infuse it as IgG?

[toomuchbaloney]

1 hour ago, adventure_rn said:

My understanding is that it has to do with kids' more immature, naive immune systems.

In adults with COVID-19, there's the initial respiratory assault, followed by a systemic immune response which harms the rest of your organ systems (heart, kidneys, etc.) and causes multi-system organ dysfunction. The sequelae remind me of a cytokine storm.

https://www.nature.com/articles/d41586-020-01056-7

https://www.newscientist.com/term/cytokine-storm/

Very young kids have relatively immature immune systems (given their limited exposures), and so they may not mount such a severe immune response to the virus.

It reminds me a bit of food allergies--the initial cause (I.e. peanuts) isn't necessarily dangerous, but the immune response itself can be fatal. In the same way, the respiratory effects of COVID might not be as dangerous as the immune response that it initiates. Little babies don't have food allergies because their immune systems are very immature; similarly, even if they catch COVID, they don't appear to mount the same catastrophic, harmful immune response. That's part of the reason why scientists are studying immunosuppresent drugs (steroids, chloroquine, and hydroxychloroquine) as treatments for COVID.

Severe COVID cases also seem to result in coagulopathy and uncontrolled clotting. This is just conjecture (I don't have any evidence to support it), but it would make sense to me that kids are a lower risk for clotting and coagulopathy simply because their CV systems are younger and healthier, with less plaque in their blood vessels overall.

Regardless, I don't think that giving older people blood from younger people would be helpful. Perhaps if we can get the blood of people who have been infected and have subsequently recovered, then we could spin it down to isolate their antibodies and infuse it as IgG?

This is what I understood too about heightened immune response. It will be interesting to watch treatment protocols evolve. We're starting to get a clearer picture of how we die from this...it's not pretty.

I sure hope some immunoglobulin therapy is useful.