> humans create a broad spectrum of antibodies against different parts of a virus and usually at least some will still bind to variants One of the big problems

> humans create a broad spectrum of antibodies against different parts of a virus and usually at least some will still bind to variants One of the big problems with our immune system is that a reaction can target markers shared with other less hostile things. Example: part of the spike protein reacts with TMPRSS2 and ACE2 on the cell membrane to smuggle the virus RNA through it. It's like a key and a door and this type of door is not only present in the pneumocytes of the respiratory system, but also in the gastrointestinal and endocrine systems, among many others. If the immune system attacks things that use this cell-membrane-access-key, the result can be a catastrophic auto-immune response leading to rather nasty long term problems and even death. From that it follows that creating a good mRNA vaccine means to identify parts for the immune system to target that are very common in virus strains, yet are also clearly distinct from those present in a healthy human. The whole mRNA tech is a major step forward and relies on selecting a piece of the spike protein unique to the virus. The old "make virus dead and consume it" approach seems primitive in comparison. However while a more specialized vaccine significantly reduces the risk of bad side effects, it is also means new variants, especially those that stick around for month, should be carefully analyzed. It is far too early to jump to any conclusion about this particular one.