The statement was made after they actually found a variant that has developed and is more dangerous than the current variety. However, the CEO went on to say that a booster should be able to handle it. I hope so.
The expectation of it “being with us” was two fold. First, the expectation that over time (still to be determine) the benefit of the original vaccine would wear off and need a ‘boost’.
Second, as was said, RNA viruses, by their nature, mutate on almost a constant basis as they multiply. The more hosts, the more replication, the more mutation. Just based on the large numbers, some of those changes are going to ‘stick’. The mRNA vaccine is meant to replicate certain aspects of the virus so the body learns to recognize and more quickly respond to it. If the pieces ‘replicated’ change, the body will not recognize the new ‘variant’.
The good news is the mRNA vaccines are polyclonal so can stand some level of changes....but only so many. The other good news is the mRNA process allows the vaccine to be quickly updated. Open question is what level of testing will be required to roll out. Plus, how do you roll out a booster, while you are still inoculating first time people? Quite a conundrum!!