He was also curious as to how people would react, he said.
"What I discovered? There are a lot of feral self-righteous zealots on both sides who are happy [to] sh*t on anyone who disagrees with their hard done research and facts."
King - also a well-known mental health advocate - said he ended up deleting the post as he found himself reassessing the sanity of people he once thought to be kind and caring self-minded Kiwis.
"Hopefully they'll be handing out chill pills along with the vaccine - I'm gonna need one."
King's experience comes less than 24 hours after an Auckland City councillor revealed he had copped online abuse from conspiracy believers for supporting the Covid-19 vaccine rollout.
Manukau ward councillor Fa'anana Efeso Collins told the Herald yesterday he had received a number of angry messages from some people in South Auckland - attacking him for his pro-vaccine stance.
People had gone as far to attack his personal beliefs.
"I've received a number of messages today with people saying the church should ex-communicate me and calling me to repent for supporting a vaccine rollout in South Auckland," he said.
"The thinking is the church should shut its door on me. That whole: 'Fraud, he doesn't belong here, he's not one of us' [mentality]."
Collins said he was not surprised about the situation, as he had been communicating with people who believed in conspiracy theories since last year.
"All I'm trying to do is provide a platform where they feel like they're being heard. But over the last few days, it's really taken quite a sour turn."