AFAIK, variants are not "resistant" to vaccines, they are just different, so a vaccine targeting the previous strand will be less effective because it doesn't m

AFAIK, variants are not "resistant" to vaccines, they are just different, so a vaccine targeting the previous strand will be less effective because it doesn't match perfectly. There is no better vaccine than the one for the current dominant variants. You can't really target future mutations because you don't know what the future mutations will be. You can imagine restricting the best, most current vaccine to the rich to limit escape mutations but besides the obvious ethical concerns, the virus will mutate anyways. Better vaccinate everyone with the best, because the less people infected, the less chances you give the virus to mutate.