Just extrapolating on your thought. The current jab spike protein creates more of them and trains your defenses specifically for that one. Now we have the new one out of Africa that they are already saying they will need a "modified" vax for. So, using the same MRNA technology, you take that one also. Now you have competing MRNA working in your system.
Does your defenses just blow a fuse and shut down, or reset into something in the middle, and what would that look like. Or does your body go to war with itself. Now if this was a traditional vax, I would be less concerned because it would present itself as two different viruses and your body would just say ok and deal with the new one also. But this is different....