When she sat with The Washington Post's Sarah Parnass and Alice Li, Stein explained her stance on something that had flared up during a Reddit AMA. Did she think vaccines were harmful?

"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."

Stein's warning about corporate influence in the vaccine approval process is often voiced by "anti-vaxxers." In reality, most members of the Vaccines and Related Biological Products Advisory Committee work at academic or medical institutions, not drug companies. But for Stein, the fact that people saw corporate and lobbying influence running rampant meant that some skepticism was warranted.

"Monsanto lobbyists help run the day in those agencies and are in charge of approving what food isn’t safe," said Stein, whose platform calls for a moratorium on genetically modified organisms (GMOs). "There is rampant distrust of our institutions of government right now. The trust level for the presidency is somewhere around 15 percent. The strong confidence in Congress is somewhere around 4 percent, and the same is true of our regulatory agencies."

Stein went on to explain that she'd studied the value of vaccines and come out with questions.

"As a medical doctor, there was a time where I looked very closely at those issues, and not all those issues were completely resolved," Stein said. "There were concerns among physicians about what the vaccination schedule meant, the toxic substances like mercury which used to be rampant in vaccines. There were real questions that needed to be addressed. I think some of them at least have been addressed. I don’t know if all of them have been addressed."

The point, she said, was that the voters who doubted that government could be trusted to make clear decisions, without meddling by lobbyists, needed to be heard. Even when it came to vaccines.