9 million - including many children, and mostly people of colour - die each year of starvation. Where's the emergency, trillions and unprecedented worldwide cooperation and effort to eradicate that forever within less than a year? It doesn't even require the invention of anything new, and is primarily a logistical (/expense) problem. Would save three times as many lives just in the first year, overwhemingly more life years overall, and be much easier to implement, being confined to mainly a few known, poorly-resourced areas (rather than the entire earth).
If you've seen or lived the effects of starvation firsthand, you'd find it difficult to understand why suddenly everyone is willing to do anything, even destroy their own livelihoods or take rush-developed intravenous shots, to try and save the lives of a significantly smaller number of predominantly elderly people who were about to die of just about anything else anyway, at the expense of those 9 million (or any other of preventable causes of death that kill in higher numbers per year and have been known about for decades, for example: smoking).
Why not spend a year making the manufacturing of cigarettes illegal, have a worldwide crackdown with cigarette company executives hauled to jail for crimes against humanity, make it illegal to depict smoking in any media, censor all images of cigarettes, and launch a 24/7 every news channel, every street corner propaganda campaign, with celebrities publicly blacklisting smokers?
Save significantly more lives in the first year, and keep doing so year after year. Wouldn't need to trash the economy, ruin businesses, or risk plunging anyone into poverty, etc - and no need for anyone to take a rushed, long-term untested shot.