If I had my way she would get a series of injections alright, but that would be lead injections from a firing squad.
I wouldn't go that far. There is no doubt that Jacinda Ardern is an ungodly leader, and also no doubt that she will face a stern day of reckoning with God someday, but remember what Paul wrote about the need to pray for those in authority:
I exhort therefore, that, first of all, supplications, prayers, intercessions, and giving of thanks, be made for all men; For kings, and for all that are in authority; that we may lead a quiet and peaceable life in all godliness and honesty. For this is good and acceptable in the sight of God our Saviour; Who will have all men to be saved, and to come unto the knowledge of the truth. (1 Timothy 2:1-4)
Remember that Paul wrote this at a time when very wicked Roman emperors were in charge. They were probably every bit as evil as some of today's leaders. Maybe even more so. Yet he didn't wish death on them or exhort Christians to rebel against them, but instead instructed that we should pray for them. We should do this so that we can live our lives freely as the Lord wants us to, but also because perhaps they might get saved. God would far rather that people get saved than that they die in their sins. A couple of other Scriptures about that:
The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance. (2 Peter 3:9)
Say unto them, As I live, saith the Lord GOD, I have no pleasure in the death of the wicked; but that the wicked turn from his way and live: turn ye, turn ye from your evil ways; for why will ye die, O house of Israel? (Ezekiel 33:11)
I realise that the chances of Jacinda Ardern getting saved are pretty remote, but you never know what God might do in her heart if enough Christians pray for her. Remember that her soul is at stake in the ongoing spiritual war between God's kingdom and Satan's. And her soul is as precious to God as anyone else's. She was brought up as a Mormon. The Mormons happen to use the KJV, although they rank it a distant fourth in their estimation behind their other three main "holy books". So perhaps there was one in her house when she was growing up. Maybe, just maybe she occasionally glanced at it or heard it read. Perhaps some seeds were planted in her heart that God could yet use if ever any "good soil" were found there.
It doesn't matter how you or I might personally feel about her. We should still pray for her. She is an enemy of Christ, for sure, and as such, an enemy of ours, but we should love our enemies, and that includes praying for them. Now if she doesn't repent and her heart becomes even harder the way the Pharoah's did in the early chapters of Exodus, then in due time, God will deal with her. However, as long as she leads our nation, we should continue to pray for her. But of course, that doesn't mean we can't feel grieved at wicked things she says or does.
I do however agree with the rest of your post, and also with Jeanne's speculation that the politicians and celebrities who make a big show of getting their jab are probably getting a placebo. I don't think there's any way to tell, either, so it is a deception they could pull off very easily.