Twitter bots and Russian trolls are fueling anti-vaccination conversations online, a new study reveals.

Most Americans recognize that vaccines are safe and critical to preventing disease outbreaks and protecting public health.

But since 2009, the proportion of so-called anti-vaxxers has increased notably in several parts of the country, and measles outbreaks are suddenly reappearing worldwide.

The debate over shots has become dramatically more heated and if social media activity were your measure, you might think that anti-vaxxers are winning.

In fact, anonymous spam bots and Russian trolls are behind an out-sized proportion of social media activity against vaccination, according to the revelatory study published today by George Washington University.

Twitter bots and Russian trolls are fueling heated online debates over vaccination as rates of shots fall and cases of once-eradicated diseases like measles rise, a new study reveals

And their automated stance on the question of vaccination may actually have little to do with beliefs about medicine. Instead, these bad actors may just be seizing on a hot topic to make money or, in the case of Russian accounts, sew discord.

Even if their intentions are divorced from medical concerns, their activity could - and may already - have dire consequences for public health.

'Social media has had a very important amplifying effect,' says Dr Peter Hotez, director of the Texas Children's Hospital Center for Vaccine development, a vaccination advocate and father to an adult daughter with autism.

'Both Twitter and Facebook put on a lot of misinformation about these implausible scenarios in which vaccines cause autism.'

Strange things are happening in the world of infectious diseases.

In the first half of 2018 alone, there were 40,000 cases of measles in Europe - far exceeding the numbers for each full year of the last decade.

The viral infection was declared 'eradicated' in the US in 2000.

But suddenly 107 cases have cropped up since January.

'That's an absolute train wreck,' Dr Hotez says.

'And it's in keeping with the US rise of the anti-vaxxer movement.'

The 'movement' began in 1998, when now-discredited (and also now-boyfriend to actress Elle Macpherson) Dr Andrew Wakefield and his colleagues published a paper purportedly linking the measles, mumps and rubella (MMR) vaccine to autism.

His research has been thoroughly and repeatedly debunked, but the fear and uproar it started has stayed in motion.

HOW HAS RUSSIA USED SOCIAL MEDIA TO INTERFERE WITH US POLITICS? Intelligence agencies have determined that Russia interfered in the 2016 elections. Fake Facebook and Twitter accounts were used to quickly spread disinformation. Bot accounts and Russian trolls posted messaging in favor of then-presidential hopeful Donald Trump during the election. Officials suspect these these accounts also stoked conversations about controversial topics in order to stoke division in the US. Yesterday, Facebook announced that it had removed 650 pages and groups that were spreading false information. Tuesday it claimed to have caught and ended Russian cyber attacks on conservative groups. A former Facebook executive has already warned that it is 'too late' to keep Russia and other malevolent parties from meddling in the 2018 elections. Advertisement

Now, it even has its own lobby, which has gained shocking traction in Texas and 17 other states where there are non-medical exemptions to state requirements for children to get the MMR vaccination.

And rates of unvaccinated children are rising in Texas, 12 other states and the country of Italy, which recently declared that the shot would no longer be mandatory.

The anti-vaxxer movement perhaps speaks loudest on social media platforms.

'Americans have a strong consensus regarding the safety and efficacy of vaccines,' based on slow but exact Pew Center polling data, says Dr David Broniatowski, lead author of the new study.

'However, if you look at social media you see a lot of anti-vaxxers, and that means that either the survey researchers aren't doing their jobs very well, or the other possibility is that the discourse on social media is being amplified'

His research points sharply at the latter.

Looking at tweets from July 2014 through September 2017, Dr Broniatowski and his team found that bots, content polluters (accounts designed to draw clicks and pull users toward malware) and Russian trolls were tweeting about vaccination, in general, far more than the average Twitter account-holder.

'So there is a large number of accounts out there tat are not representative of real people,' he explains.

'Bots and trolls mean that a small number of people can operate a large number of accounts and make it look like fringe opinions are actually mainstream,' he says.

Bots and content polluters tended to tweet mostly anti-vaccination statements, while the Russian trolls tweeted about both sides.

The Russian-backed trolls don't care so much whether or not Americans get vaccinated, Dr Hotez and Dr Broniatowski agree. They have a bigger goal in mind: sewing general discord.

'This clearly has very destabilizing effects,' says Dr Hotez.

'Who knows what the real motive is, but I would argue if the desire is to destabilize the trust in the government in the US and Europe, this would be an effective way to do it.'

But this conflict does trickle down more immediately to not only polarize groups, but dissuade them from getting vaccines.

'We have solid research that when you expose people to the vaccine debate, even though they may not necessarily agree, it does promote uncertainty and less trust in healthcare providers,' says Dr Broniatowski.

People exposed to the debate 'say they intend to get vaccinated, but they may delay, and once you have delays, it'sin that period that the population is still susceptible to disease, and that could lead to epidemics,' he adds.

'And those epidemics don't necessarily respect national boundaries.'