An 18-year-old from Ohio who famously inoculated himself against his mother's wishes in December says he attributes his mother's anti-vaccine ideology to a single source: Facebook.

Ethan Lindenberger, a high school senior, testified Tuesday before the Senate Committee on Health, Education, Labor and Pensions, and underscored the importance of "credible" information.

In contrast, he said, the false and deep-rooted beliefs his mother held - that vaccines were dangerous - were perpetuated by social media. Specifically, he said, she turned to anti-vaccine groups on social media for evidence that supported her point of view.

In an interview with The Washington Post on Tuesday, Lindenberger said Facebook, or websites that were linked on Facebook, is really the only source his mother ever relied on for her anti-vaccine information.

Most importantly, Lindenberger said, was the impact Facebook's anti-vax communities had on his family.

"I feel like if my mom didn't interact with that information, and she wasn't swayed by those arguments and stories, it could've potentially changed everything," he said. "My entire family could've been vaccinated."

Lindenberger said that he believed his older siblings, who predate Facebook, had been vaccinated. He said his younger siblings have not.

The Centers for Disease Control and Prevention explicitly state that there is no linkage between vaccines and autism, and also warns of incorrect information that is easily spread and made available online.

"I didn't agree with anything he said," Jill Wheeler, Lindenberger's mother, told the Associated Press. "They've made him the poster child for the pharmaceutical industry."

Wheeler was not available for comment before this story was published.

The Washington Post has previously reported on the ways Facebook has served as a place of refuge for parents who reject facts on immunizations.

Lawmakers and medical professionals have pressured the platform over the spread of misinformation related to vaccines, especially targeted advertisements and anti-vaccination materials aimed toward women in regions with high numbers of measles reports.

"We've taken steps to reduce the distribution of health-related misinformation on Facebook, but we know we have more to do," Facebook said in a statement to The Post last month.

The platform said it was considering reducing the appearance of anti-vaccination material in search results and 'Groups you should join'.

Facebook came up several times in Lindenberger's testimony before Congress on Tuesday.

"Does your mother get most of her information online?" asked Senator Johnny Isakson.

"Yes. . . . Mainly Facebook," Lindenberger replied.

"And where do you get most of your information?" Isakson asked.

"Not Facebook," Lindenberger said, laughing. "From CDC, World Health Organization, scientific journals and also cited information from those organizations . . . accredited sources."

He testified that his mother had vocalized her anti-vaccination views over the course of his entire life and that over time he began to notice that the benefits of vaccinations outweighed the perceived risks.

This became apparent when his mother would share videos and people would dispute her claims in the replies.

"It was really frustrating for me," Lindenberger told The Post. "I knew if I were to continue arguing and push my stance, even if it was correct, I wouldn't get anywhere."

In his testimony, he said he approached his mother repeatedly in an attempt to sway her views. In one instance, he cited the CDC. His mother replied, 'That's what they want you to think.' "

In arguments with his mother, Lindenberger said she would repeatedly make claims and rely on information from Facebook that had no real attribution or backing. Some of the facts are conspiracy theories, including a claim that the CDC is funded by Big Pharma, who pays the agency to push vaccines.

"She didn't trust any sources," he told The Post. "She thought vaccines were a conspiracy by the government to kill children."

Lindenberger said his mother is not unique and that many are swayed by information falsely presented on Facebook to be accurate. This baseless data is often supplemented by graphs and charts that make the claims appear to be factual.

The renewed conversation on vaccines comes amid a resurgence of the measles - which was eliminated in the United States in 2000 - spurred by an increased number of people who travel outside the country and bring the disease back, according to the CDC. The spread of measles is exacerbated by what the CDC describes as "US communities with pockets of unvaccinated people."

A recent measles outbreak in Washington state, one of six ongoing outbreaks in the United States, has affected 71 people, the state's Department of Health reports.

The epicenter of that outbreak lies in Clark County, an area near Portland, Oregon, that officials have dubbed an anti-vaccination "hot spot" because of the high rate of non-medical exemption from required vaccines.

There have been 206 confirmed cases of measles reported in the United States, spanning across 11 states, the CDC reports.

Lindenberger said Facebook needs to continue its push to crack down on misinformation regarding vaccines, particularly allowing it to be shared in a way that "looks legitimate."

"People can skim over that, but it's a huge problem," he told The Post. He added there needs to be more clarity on sourcing, separating falsehoods from "actual scientific journals."

Taylor Telford, Isaac Stanley-Becker and Lena H. Sun contributed to this report.

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This article was originally published by The Washington Post.