Seems like Clintonite Liberals distorted a quote to try to sabotage her in 2016. To quote some article I found (who also couldn't find a concrete origin of the claim):

“I think there’s no question that vaccines have been absolutely critical in ridding us of the scourge of many diseases — smallpox, polio, etc. So vaccines are an invaluable medication,” Stein said. “Like any medication, they also should be — what shall we say? -- approved by a regulatory board that people can trust. And I think right now, that is the problem. That people do not trust a Food and Drug Administration, or even the CDC for that matter, where corporate influence and the pharmaceutical industry has a lot of influence.”

[–] Evilphd666@hexbear.net 3 points 3 months ago

Stein is a havard trained medical doctor. She knows we could make vaccines better, safer, but because we have a corrupt AF corporate captured regulatory body, they allow lower quality higher profit margin vaccines.

So the Democrats try to paint her as "anti vaccine" to deflect from their culpability in that corruption.