I've met one, she's the English teacher at the school I work at.
She has a half black kid, hates Trump and constantly compares him to Hitler during the mandatory annual holocaust unit, and thinks everyone on the right is racist and hates her kid.
Yet simultaneously, she is the most anti-vaccine person I've ever met. Not just in terms of the Covid vaccine, she hates all vaccines.
Her line of reasoning basically boils down to, "It's my decision, and if your vaccines are so effective then just take them yourself and don't worry about what me and my kid do."
I've never met or even heard of someone on the left who's anti-vaxx, I really thought it was specifically a right wing phenomenon for the longest time, so it caught me off guard when I first heard her start ranting about them.