"I just remember being very scared."

That's how Lydia, a 39-year-old mother of three in Canada, describes feeling when she was pregnant in 2008 with her daughter and had questions about vaccinating. She worried it might cause more harm than good.

"I remember feeling some trepidation and saying to my husband, 'We can't undo this once we do it,' " she says. NPR is not using Lydia's full name because she's worried about backlash from a community she once believed in — people opposed to vaccines.

The record-speed development of the COVID-19 vaccine has some asking questions about it as well as about the safety of all vaccines. It's something that's taken root and grown because there's a natural incubator inside the broader movement opposed to vaccines.

"We have been seeing an increase in vaccine-hesitant conversations online," says Kolina Koltai, a misinformation researcher at the University of Washington's Center for an Informed Public. "Vaccine-opposed communities online saw a growth in membership, and it has become easier to be exposed to vaccine-opposed content."

One survey finds 71% of people say they'd likely get the COVID-19 vaccine, but still medical experts have been working hard to combat the perception that the rapid creation of the COVID-19 vaccine makes it less safe.

"The speed is really a reflection of the scientific advances that have allowed us to do things in a matter of months that would have formerly taken years," Dr. Anthony Fauci told NPR in December. "That isn't reckless speed; that's sufficient speed based on scientific advances."

For Lydia, the pandemic is what ended up leading her out of the movement among those opposed to vaccines.

But getting there was a years-long search for answers.

A decision to vaccinate questioned

Lydia didn't always question vaccines. She'd worked in a pharmaceutical plant as a quality control chemist. She even got vaccinated for the flu while pregnant.

Having a baby in 2008 made the decision more complicated for her. She voiced her concerns to her husband, but in the end they went ahead. She made an appointment, and the pediatrician gave her 8-week-old daughter three vaccinations. A few hours later her daughter was crying a lot, what she describes a high-pitched squeal. It was a type of cry she'd never heard before.

"It was quite traumatic. She screamed and cried," she says. "I felt horrible."

That horrible feeling didn't go away when a public health nurse she called tried to assure her that these reactions were normal. It still didn't sit right. Lydia says she felt brushed off, her concerns minimized by the nurse.

Her daughter was fine, but at the time, Lydia wasn't convinced and took her questions to an online forum for new moms. It was there that she read a lot of frightening information about alleged and unfounded harm vaccines can cause. They described terrifying symptoms — such as high-pitched screaming. She began questioning her decision to vaccinate.

"So then you start thinking, did I just hurt my child?" she says. "They give you an answer that the other people couldn't give you or didn't give you. And so now you don't have any trust."

Lydia began going deeper into these forums where people shared what she thought were convincing studies that made claims about the damage vaccines can cause, studies she now realizes were false. But back then, it was proof enough for her not to finish her daughter's vaccine cycle.

"I think sometimes doing nothing is easier because you don't feel as responsible for the outcome," she says. "If you give your child a vaccine and they suffer a consequence, that's your fault. A parent would say, 'I did this to my child.' So I think that there's an appeal to inaction that makes it easy for a lot of parents to not vaccinate their child."

''Out of my echo chamber''

Lydia had a second child eight years later, a third a few years after that. She wasn't planning on vaccinating them either until the pandemic hit last year. She saw the news of people hoarding toilet paper and other supplies and read apocalyptic speculation about the collapse of health care systems and sanitation. She was worried about diseases coming back that she had not vaccinated her kids against and went looking for answers again on the Internet. But this time it was different.

"I got out of my echo chamber," she says.

One of the myths Lydia had believed is what many of these groups believe about the blood-brain barrier. In short, their theory is that the membrane protecting the brain is not mature enough at birth, and therefore ingredients in vaccines can leak into the brain and cause harm. Studies have shown this is not true.

Lydia found some of these studies and realized she was wrong. And that moment became a bit of a revelation.

"That really was the catalyst to just keep going with the research and consider for a moment that maybe I'm wrong, even if it is embarrassing, even if it is uncomfortable, that I could be wrong about more things," she says. "And that was hard. That is hard."

Finding reassurance

Lydia says it was difficult confronting something that had been a part of her identity and beliefs for more than a decade. It was a reality she had built up for herself and her family, one that she thought was keeping them safe.

"It's almost like thinking like you have this cheat code to keep your kids healthy from disease and allergies," she says. "You feel like you've got a way to game the system to avoid all that. It does kind of become a large part of who you are."

Koltai, the misinformation researcher, says this attachment to identity is a consistent throughline she's seen in her research on misinformation and groups opposed to vaccines.

"If you subscribe to the ideology that vaccines are not safe, necessary or efficacious, you will find yourself being ostracized or forced to hide this belief from those in your community until you find a community of people who have the same shared values and beliefs as you," she says.

Even after she made appointments to get her three kids caught up on vaccines, Lydia still had some doubts. She needed just a little more reassurance that she was doing the right thing.

She found it in the spring in a short TikTok video about vaccine safety that Cincinnati pediatrician Nicole Baldwin had posted early last year.

"She just really wanted reassurance," Baldwin says.

The video had gone viral and got a huge, mostly positive response. Baldwin shared it on other platforms such as Twitter — and on Facebook, where, she says, she also saw a backlash.

"I got death threats on the platform. People called my office and harassed my staff. We had to call the police," she says.

Baldwin says the false information about vaccines that circulates on social media platforms is still a problem, one that she says is fair to call a public health crisis.

"It's dangerous, and we're seeing an uptick in vaccine preventable diseases simply because of all of this misinformation that's out there," Baldwin says.

While Facebook has taken steps in recent months to combat disinformation and misinformation about the coronavirus and the COVID-19 vaccine, the company has historically struggled to handle broader anti-vaccine misinformation on the platform.

''Is this true?''

January has been a big month for Lydia. Her youngest child received his final shots to get him caught up on his vaccines. Her other kids are up to date on their vaccines as well.

And Lydia started nursing school. She wants to help parents such as herself who might feel scared to understand the facts about vaccines.

"I want to be able to tell new parents how to handle anti-vaccine rhetoric [and] how to dismantle it and see it for what it is," she says. "Without making them feel like they're talked down to or dumb."

Lydia says she is concerned about where the movement is going and the changes she's seen in the current political environment. She says things have changed a lot.

"When I started, it was very motivated by moms wanting to be natural and hippie-like, whatever you want to call it," she says. "And now it's been totally infiltrated by right-wingers that it's a constitutional, health freedom movement. And, you know, a lot of them believe in conspiracy theories and flat Earth. It's scary."

The experience also created a conversation between Lydia and her daughter, now 12, about being able to understand and admit when you might be wrong.

"I definitely use it as, like, a lesson [to] make sure you have all the information, even if it's information that makes you uncomfortable. And ask yourself, before you share anything: Is this true?"

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