People will tend to accept anecdotal information from a friend over peer-reviewed science because the former has much greater credibility to the average person - thanks to how our species developed.
It is a decade old but the book "The Invisible Gorilla" addresses these issues (including the origins of the anti-vaccine movement) and explains why we are not as smart as we think we are and why the intuitions we are told to listen to more often than not lead us astray. Topics include financial investing, eyewitness testimonies and others that show why science is dismissed and unscientific and provably false "advice" from a trusted source is accepted.
People don't like to hear this but our belief in own own decision-making prowess is greatly overblown. One of my favorite examples involves "multi-tasking" that began with David Strayer's research into distracted driving. Strayer found that those individuals who were most convinced of their ability to multi-task were in fact those who were the worst at it. In fact, less than 2 percent of people can actually perform multiple tasks at once and do them successfully. But the majority of people believe they can.
So misinformation can now be spread to millions on social media by trusted sources like yoga teachers or celebrities who are completely misinformed, and people will buy into it because they think they ARE making an informed decision. That includes people who are considered intelligent in other areas.
I highly recommend the book by Chris Chabris and Daniel Simons:
https://www.amazon.com/Invisible-Gorilla-How-Intuitions-Deceive/dp/0307459667