Mutations? I believe that’s why the flu vaccine hasn’t eradicated the flu.
I believe in a simplistic sense (the level of most of us) this is the best answer.
I agree with mutations being a factor in reinfection. If this is the case the new variants should be renamed COVID-20, COVID-21, etc. This logic would also allow one to conclude the following. If you bodies immune system can not address mutations, why should we believe vaccine could?
Because it was manufactured to be different. Take the common cold virus, tag some serious influenza like respiratory and hemoglobin symptoms to it and release to the world. It will be very infectious, you’ll just keep getting it just like you do colds, there will be no vaccine or large build up of antibodies and you’ll get deathly ill like the swine flu.
Thanks China.