There are currently over 880,000 registered COVID deaths in the US, and every day another 2-3000 more are added to the tally, so it is very likely that by November, there will be over 1 million COVID deaths. Overwhelmingly, these deaths are the unvaccinated: around 9 in every 10 deaths are unvaccinated. On top of that, whether US citizens get vaccinated is heavily impacted by their political affiliation: whereas 90% of Democrats are vaccinated, fewer than 60% of Republicans are, and nearly all of the remaining unvaccinated Republicans don't plan on getting vaccinated at all. This means that a large amount of COVID fatalities will be Republicans, even accounting for the initial periods where vaccines were not widely available yet.
Considering how close certain senate races have historically been, how likely could it be that in some of the races won by Democrats, the difference in vote count is lower than the number of Republican deaths in that seat's area, meaning that the lack of desire of Republicans to get vaccinated has had a material impact on the results?