Coronavirus Variants, the How and Why of It
The coronavirus immunologically is essentially all about the spike protein. However that antigenic site sits atop a "stem" which is longer than that of the original coronavirus. This stem is probably where all the variants arise. Let me explain. As we've said, the spike protein is the site that's recognized by the immune system and variations of it are unlikely to produce successful variants because the spike protein is already very adept at latching onto our Ace-2 receptors--any changes would probably degrade this ability rather than enhance it. [the caveat here is "any natural changes," but when manmade, all bets are off. More on this later]. So, what is the source of the variants such that the impact on immunological surveillance is significant while still allowing for Ace-2 receptor binding? What role does the stem play in all this? In previous posts, I've pointed out how that elongated stem results in a lower density which allows the virus to remain...