UK Health Security Agency Using Existing Failed Vaccines

The Modified Ribonucleic Acid (mRNA) injection programs the cells in the human body to produce a spike protein that is an exact, replucated, match to the coronavirus spikes so its effects can be countered. Variants occur when the coronavirus protein spikes mutate creating a new strain. How can an existing mRNA, created for the first coronavirus strain, be effective against a new strain?
Is anyone going to fall for this rubbish again?