Revelation 20:4-6. While Satan is imprisoned for a thousand years, the souls of those who were beheaded for testimony to Jesus and God, and who had not received the mark of the beast nor worshiped the beast, come to life, and appear with thrones on which are seated those to whom judgment has been committed. These souls will reign with Christ for a thousand years (this is the First Resurrection, the rest of the dead will not rise until the Second Resurrection, which will happen after the thousand years). The second death has no power over those who rose in the First Resurrection.

This reading comes at the end of the tribulations of Revelation.The only remaining tribulation before the full establishment of the Kingdom of God is Satan being loosed after the thousand years and attempting a last stand against the holy ones, but that is put down quickly by God. So while this is describing the holy ones throughout time, all of whom will rise and reign with Christ during the "thousand years," it is particularly relevant for those who live and die in the time of the "mark of the beast".

As usual, this reading can be applied to many times throughout history, but also describes a particular time that will happen. There have been holy ones who have never worshiped the beast and who have never received his mark since the beginning of time (and his mark can manifest in history in subtle ways which serve as "types" of the mark - they are like the mark, and serve to warn believers of what the mark will be like and how easy it will be to be seduced into receiving it. But there will come a time when the events of Revelation are playing out with particularly, and when there is the literal mark of the beast, resistance to which will be especially difficult.

I don't think the vaccine was the mark of the beast, although some thought so. It is defintely a "type" of the mark, though! I think it was meant to prepare us for the mark, which may be a chip in our heads, or some other digital implant that will be used to work the "signs of deception" on those who have received the mark and worshiped the beast (see Revelation 19:20). It is worh noting that you can receive the mark without worshiping the beast. After seeing the coercion and deception surrounding the vaccine, I think that will be true of many people. They are not doomed, but they also will not rise during the thousand years - they will be judged at the final judgment, the Second Resurrection, while the holy ones who rise for the thousand years will have nothing to fear at that time. I also don't think you will have to have been literally "beheaded" for testifying to Jesus to be one of the holy ones, I think it will be enough to have been martyred in some way (and there are many ways to be martyred!).

I think this section describes a lot of people who are testifying to the truth in our times. When great evil abounds, God raises up great saints, and I believe those holy ones are all around us, and are being or will be martyred for testifying to Christ. I wouldn't want anyone reigning for a thousand years but those who were som committed to the Truth that they were able to resist the beat and his mark, even if it meant death!