A few comments here. Everyone is trying to understand immunity. Its complicated, and there is not a lot we know about it. Coronaviruses are particularly tricky. However, ask yourself this question: why were there no successful coronavirus vaccines in animals or humans prior to 9 months ago? It certainly was not for lack of trying.

(1) First we start with common cold coronaviruses. These infect 30-40% of the population yearly (or at least they used to). Generally nobody dies from infection, but repeat infections are common. Additionally, if you are immune compromised, obese, or very old, you tend to sometimes do very worse than usual.

(2) This means that we never get long term sterilizing immunity to coronaviruses. All of the animal experiments done have very short timeframes. The B cell response is transient, as we have seen. So what is really happening?

(3) Your body is continually trained by repeat infection to (a) have trained non-specific innate immunity, which lowers viral load; and (b) to have adaptive memory CD8 T cell effector immunity, which kills off virally infected cells and prevents you from getting very sick or dying. In some people (ie children) this is so strong you dont even know you had an infection.

(4) Vaccination to the spike gives a short term burst of sterilizing immunity at a cost of immunosuppression between doses 1 and 2 (for reasons we dont quite understand, likely due to a natural reaction to tamp down immunity). Spike vaccination also creates B and T cell memory only to the spike, and it is very narrow. This allows immune escape from antibody neutralization, and thus the repeat infections. However, after dose 2 you get a CD8 T cell response to the spike, which is likely long lasting. Thus, most people who get infected with escape variants will have mild disease.

(5) Natural infection gives broad B and T cell immunity, but the B cell response is shallow (if it was too great we would all die of severe immune reactions). Thus it is not quite sterilizing. However, just like with the common cold, repeat infections build a strong memory CD8 T cell response, so you dont get too sick going forwards.

(6) The only way out of this mess is repeat exposure to naturally occurring variants of the virus. Just like the common cold.

(7) Vaccines to the spike will give you a short term burst of sterilizing anti-spike antibodies, at the cost of these antibodies causing severe complications in a small number of people. This is why we never had a vaccine to the common cold.

(8) However, in the vulnerable, there may be enough spike CD8 T cells created after two shots to ameliorate severe disease, since these people have trouble mounting their own natural immune response. Everyone else likely needs very little, and we have to balance these serious auto-immune responses with the burst of sterilizing immunity that is transient.

Its been a long ride, trying to get everyone grounded in molecular biology, virology, immunology, and therapeutics. Problem is the corruption in politics and medicine is seemingly insurmountable

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