People tried to compare the COVID vaccine development time to previous vaccines without understanding the difference in how the mRNA vaccines are made. You essentially just need to sequence the virus’s genome (which is miraculously easy to do these days because of other amazing people’s incredible efforts), then target a protein from the virus’s exterior and use that snippet in the mRNA vaccine. This radically reduces the time it takes to develop a vaccine as well as increase it’s effectiveness because of the control you have over the vaccine’s selected target.