i was thinking the same about the abstract, the glycans were shielding the conserved parts epitopes that arnt prone to mutations, as opposed to the exposed parts of the proteins which the virus mutates much more rapidly. you can say the conserved parts can mutate, but it might compromise the structure of the protein, making the virus defective(it probably does happen, but they dont survive)

Does the sugar stripping affect any other bodily functions? Stripping is temporary but it still may have permanent effects for some existing conditions.

Does a coronavirus need to be introduced at the same time sugars are stripped or is it assumed that there are already many in the body?

I've learned a lot more about virology, vaccines, and immunology in the past 5 years than I ever thought I would need/ want to know, mostly from listening to the brilliant folks over at Microbe.TV (https://www.microbe.tv/), with This Week in Virology, and the other science based podcasts they produce.

The glycan camouflage is less effective once the immune system has been exposed to the spike protein, and "knows" what to look for, so it can mount a response, through the T and B cells.

Awe, thanks for your 'support'.

As I understand it, "hidden" is a relative thing. Before exposure one's immune system doesn't know what to look for, after exposure, and immune response, one's T and B cells have a much better chance. That's why denovo immune response to an epitope may not be sufficient, but once the immune system has been 'exposed' or 'educated' the response is much more specific. There are two parts to the immune system, innate, basically structural, and adaptive (T's and B's) that can be primed with certain factors to create a very precise response. The long term nature of immune response is dependent on those cells, which come in number of different 'flavors'. Tissue Resident Macrophages hang out in the area of initial infection, waiting for "that guy" to show up again. They can sit relatively dormant for years. I don't want to mislead, our understanding of the long term memory function of the immune system isn't completely understood. And so we don't know how long a given immune response will last, at least not yet. Does that help? I'm not an immunology prof, or researcher, so I may not have been clear.