They still died from Covid Fool. Vaccines are not the end all be all.
No one ever said the vaccine is 100% effective. They've always said it's like 90% effective. That's been the news reports since the beginning.
Vaccines are like bullet proof vests. You take a couple bullets to the chest (catch covid) and you can potentially still survive as opposed to taking bullets to the chest without a vest on.
You can however still get head shots that will take you up on outta here (headshots in this case meaning extremely high viral load that the vaccine and your body can't handle).
However when you know bullets are flying (meaning, covid is running rampant), you would rather have that vest on than not have it on. A good chance of survival is better than no chance of survival.