Control. They want complete control. This first round of injections is being used to put everything in place to force the mandatory yearly injections. Once there are mandatory yearly injections, they'll be able to control the demographics of every country, state, city, and neighborhood. If an area has too many of an unwanted demographic - Be it age, race, religion, political beliefs, dissidents, wrong thinkers, etc. They will be able to "adjust" those demographics using their mandatory yearly injections. Early deaths, a drop in fertility rates, etc. They don't need to genocide an entire area. By simply "adjusting" the fertility rate of an area slightly lower, they'll be able to change the racial and religious demographics of that area in a decade. By slightly "adjusting" the life expectancy of an area, they can greatly change the political leaning, and the healthcare costs, pension, and other government expenses an area uses. Again, once the mandatory injections are in place, they will be able to easily "adjust" the demographics of any and all areas in the world. With the "adjustments" being subtle enough for people to not notice. Not every injection is poisoned right now. Not every injection will be poisoned in the future. Once mandatory injections are in place, the percentage of poisoned injections will all depends on the amount of unwanted demographics in an area.