I found the pacing of the first book to be too slow for me as well. The first one or two stories were properly paced in my opinion, but then it felt sluggish. That being said, the show makes a few changes to the story and it doesn’t change the story overall, but it does give a more action feel to it rather than a slow mysterious dystopian drama.
Actually it’s worse than that, if you have enough unvaccinated people in an area you’ll increase the viral load received by the local population. Vaccines raise immunity significantly, but don’t make you fully immune. If you experience enough of a viral load despite being vaccinated you can still get sick. This is how outbreaks occur and why we’re seeing them in low vaccination communities. These viruses then spreads to others that shouldn’t normally get the virus. So in short it harms everyone including those vaccinated.