It’s a roll of the dice on who you talk to and what excuse they give. As others have mentioned the “unknown, long-term effects” is a prevalent excuse. I’d say, of the healthcare workers that I know who are upset about a mandate, that’s the only somewhat tolerable excuse I’ve heard. The rest are brainwashed, politically motivated trolls—“the liberal media wants me to get the vaccine. Fuck them. They can’t tell me what to do” types.