Hopefully they can establish the immunity thing soon, it is a big factor for our future movements.
Hello; The antibody immunity thing is a very big piece in the outcome of this pandemic. Let me first restate that my knowledge and understanding comes from dated experience. A thing I recall of how a persons immune system reacts to a foreign invader is to eventually produce a specifically tailored thing called an antibody. The corona virus family has that name due to the crown like projections (spikes) on the surface of the viruses. At least someone saw that resemblance. It is the detailed shape of these projections that are critical.
A new virus invades our body. The virus takes over a cells manufacturing area forcing the cell to make copies of the virus. The cell is destroyed in the process and huge numbers of virus copies are made. The body at some point senses the invaders and starts a somewhat slow process. Slower than we want it to be in the sense we wind up sick for a time. I do not recall the exact sequence but a critical step is the projections (spikes) on the surface of the virus are identified and essentially catalogued. Our immune system then starts to make many defender bits called antibodies that can attach to a virus particle when they come across it. But this process takes time while the virus continues taking over cells in an exponential increase of their numbers.
Best I can recall the antibody has to get to the virus before it attaches to a cell wall to be effective. The antibody in effect locks up the virus keeping it from being able to attach to a cell. If enough antibody particles attach to the surface then the virus cannot attach to a cell.
The antibody response sort of becomes a race between the virus and the antibody. If the virus gets a good head start it may damage so many cells that the person gets very ill from their destruction. The immune system has to make a significant number of antibody particles so they can subdue the virus. May be several antibodies attaching to a single virus. Once attached, best I can recall is those individual antibodies are out of the fight for good but have done their job. The body has to keep making new antibody particles and so on. In a good outcome the immune system wins the battle of numbers and we survive. The overall damage we take in the battle is expressed by how ill we become during the battle. Currently for some reasons a few get very ill from the battle while the large majority have mild to no symptoms of that battle.
Any way if we survive the active immune response continues for a time. Might be called a mop up action. Fresh antibodies continue to be made for a time and eventually seek out the dwindling numbers of virus. (There are some additional twists that could be mentioned but not now.) Over time with no virus detected the immune system stops the production of new antibodies. Maybe the antibodies continue for months or longer and likely for at least a few weeks.
However the immune system keeps a copy of the shapes of the spikes of that particular virus in sort of storage. That way if some time in the future that particular virus finds it's way inside your body again the body can make antibodies very, very much quicker than the original immune system response took. We often do not even know we were invaded again. In effect we become immune to that particular strain of the virus with those very specifically shaped spikes.
I suppose this is where the "will I be immune or can I be infected again" question comes in. I am going out on a limb of unproven speculation from this point. My understanding is these RNA type virus are prone to change the shape of those identifying spikes fairly often. This is why we need a new flu shot each year and also part of why the flu shots are often less than 50% effective. The vaccines have to be made ahead of time so they make an educated best guess which flu strain to use to match the new vaccines with. The flu virus can change and the flu shot will not work. So the covid19 may be a talented changeling virus and our stored immune antibody copy may not work on the changed spikes. Too early to know for sure but I am voting for a positive immune response and hoping if I catch it and recover that I am then immune to that strain. ( I inject that at least one TV expert has stated there is no evidence of this covid19 drifting or changing so far. That was a couple weeks ago tho and things change with new information.) A number of other details can be mentioned but that is the basics as best I can recall.
Partial immunity for example. The coronal virus family also give us the common cold if memory serves. There are over a hundred known cold virus which is why we can get so many colds. A big unsupported guess on my part might be a common cold virus has spikes sorta similar to the covid19 and having had that particular cold gives us antibodies that are not real good, but good enough to reduce the severity of the covid19 symptoms.
One final WAG from me. Best I understand is the way a vaccine works is a variation of the bodies natural immune response. They find a way to make the virus harmless ( some problems on the harmless bit sometimes) while keeping the virus surface spikes identical. We get the vaccine injected with those identifying spikes and our immune system starts to make antibodies tailored to those spikes. My question being if the natural immune response does not turn out to work, then how will the vaccine be expected to work?
