Thread by @conspirator0

Let's take a look into the world of anti-vaccine discussion on Twitter. The first challenge here is to find the tweets; there's no obvious hashtag or term guaranteed to be exclusively associated with #antivax tweets.

cc: @ZellaQuixote

A manual review of tweets indicates that #antivax, #vaccine, and #vaccines are all hashtags that occur frequently in anti-vaccine tweets. However, there are lot of false positives (pro-vaccine tweets) in this dataset. How do we isolate the content we're interested in?

Plotting the retweet networks provides a solution. All three hashtags have networks that split into pro and anti-vaccine sections. We can filter out the tweets from the accounts outside the #antivax section to obtain the desired dataset.

Once we restrict the #antivax/#vaccine/#vaccines tweets to those from the anti-vaccine accounts only, we are left with 6054 tweets from 2017 accounts in the past ten days. What do the accounts look like?

We downloaded the most recent 1000 tweets from a sample of 1000 accounts with recent #antivax tweets. The hashtags they most frequently tweet are a mix of conspiracy theory stuff (#QAnon, #Chemtrails, the vaccine stuff itself) and current political hashtags (i.e., #GiletsJaunes).

Finally, here are the news sources most frequently linked by the #antivax accounts. Zerohedge, RT, and pseudoscience site Natural News are the most prominent; the remainder are largely right-wing conspiracy sites.

In light this suggestion (thanks, @gorskon!), we'll take a look at the anti-vax hashtags hashtags listed in this tweet.

https://twitter.com/gorskon/status/1093533577164324864

To start with, we'll download all tweets containing the hashtags for the last 10 days and plot the network in order to prune off-topic content. #bought and #informedconsent have substantial sets of false positives, so we remove those, leaving 3035 tweets from 1056 accounts.

Going back futher, traffic on these #antivax hashtags first took off in early 2015, and has spiked over the last several months. The culprit for the recent activity appears to be the theoretical upcoming release of the film "#Vaxxed2: The People's Truth".

The hashtags and media sources used by the accounts using these hashtags are similar to the anti-vax accounts using #antivax/#vaccine(s) discussed earlier in this thread. The most notable difference is that they link more antivax-specific websites.