Table 2.

Positive claims posted by Facebook users on Facebook advertisements categorized by themes (n=74)^a,b.

Themes	n (%)	Examples of claims within comments
Vaccines prevent disease risk or benefit	29 (39)	No vaccine is 100% but those vaccinated can fight the illness more effectively. Herd immunity only works when we vaccinate. I wonder if some peoples opinions would change if we lived in a country where vaccination was not common, and these diseases were common... Some parents have chosen to opt out and Polio, Whooping Cough and Diptheria are recurring. This puts us all at risk. The benefits outweigh the risks. We do not want these diseases to return with a vengeance! I personally could not live with myself if my child got very sick or died from a preventable disease to which we have access to free immunizations for...Now of course I vaccinated my kids because they can protect them from death...If they were bad...Or caused autism they would have been out of the market and not given by doctors don’t you think? I have 4 kids ranging from 18 to ten months. It’s worth the risk getting vaccinated. I’ve seen what whooping cough and polio do to people. I promise, those who’ve had polio will probably get their kids vaccinated.
Parents who do not vaccinate are uneducated or unintelligent	13 (18)	If you’re going to be an idiot and not immunize, at least make sure you’re a well educated idiot... Wow, it never ceases to amaze me how ignorant and just plain dumb some people are... It’s idiots who don’t vaccinate their kids that cause outbreaks...people think that they know more than the medical community. I find people who don’t vaccinate are some of the most uneducated nut jobs...
Follow the advice of health care providers and trustworthy sources	12 (16)	...get your information from reputable sites ie health canada or the cdc. Stay away from those “crunchy granola” opinion- based websites Research does not include google off siting an article you found on Facebook. These people don’t even know the definition of a peer reviewed research paper or study...and if you can’t tell the difference you should try and trust that the medical professionals who do know... ...everyone should read official statistics and not internet mumbo jumbo. The internet has so much bs that it can make anyone’s perception a reality... Yup our society rallies around a former porn star/actress looking to continue her 15 minutes of fame instead of putting our trust in our medical and science community...Sad state of society I’d say!
Vaccines do not cause autism	10 (14)	Jenny McCarthy made the Hollywood rounds stating her son got autism from his vaccines...Since then it has been proven her son doesn’t even have autism nor do vaccines cause autism... I have a child with autism, and do NOT believe vaccines have ANYTHING to do with it! That has been disproven! The jury is not out on autism. The verdict is no link...
I am provaccine or vaccinate	10 (14)	Be smart...Vaccinate Myself, I am a believer in vaccinations but that’s just what I believe is right for my kids...

^aWe included 2 hesitant comments with positive claims in the analysis.

^bTotal percentage does not equal 100% due to rounding.