Unfortunately, vaccines aren't all 100% protective. And there are people who get the disease even though they were vaccinated. That means that the idiots who don't get vaccinated can spread the virus to people who wouldn't have gotten sick otherwise. Which of course doesn't mean that vaccination is bad, only that it is not perfectly protective. For example, I have had all the Covid vaccinations up to the day I got Covid. I only knew I had Covid because my wife, who was one booster behind me, got sick with Covid so even though I felt fine, I tested and saw that I also had Covid. But the vaccine kept me from getting sick.
Mfw the lefty "natural" bullshit peddled by health nuts gets tacit approval from my conservative parents trying to eat "traditionally" aka raw everything.
RFK's version of the conspiracy is that vaccines are a scam inflicted by private pharma. Given his druthers, he would probably outlaw not just vaccines, but all corporation-produced medicine.
Most of those people are now all in for Trump. I'm not even sure I'd call them "left" in the way that people mean anyway, even before they became Trump supporters.