Ensuring people are vaccinated against COVID-19 is the most surefire way to save lives in the ongoing global pandemic. Still, vaccine hesitancy is holding up vital immunization efforts, and it's more important than ever to understand its source.

According to recent research, a large chunk of this very big problem actually has a very small starting point. In a new study, researchers found the majority of anti-vaccine conspiracies circulating on social media can be traced to a mere handful of individual accounts representing prominent anti-vaccine personalities.

In all, just 12 of these people and their organizations – the so-called disinformation dozen – are responsible for initiating up to 65 percent of all false and misleading anti-vaccine propaganda shared on Facebook and Twitter.

That figure is based on an analysis of over 812,000 posts extracted from Facebook and Twitter between 1 February and 16 March 2021, conducted in an investigation by the not-for-profit Center for Countering Digital Hate (CCDH) and Anti-Vax Watch, an organization that monitors the anti-vaccine industry.

"Living in full view of the public on the internet are a small group of individuals who do not have relevant medical expertise and have their own pockets to line, who are abusing social media platforms to misrepresent the threat of COVID and spread misinformation about the safety of vaccines," explains CCDH CEO Imran Ahmed in the report.

"According to our recent report, anti-vaccine activists on Facebook, YouTube, Instagram and Twitter reach more than 59 million followers, making these the largest and most important social media platforms for anti-vaxxers."

Per the research, the 'disinformation dozen' behind almost two-thirds of anti-vaccine content shared in the study window includes Joseph Mercola, Robert F. Kennedy, Jr., Ty and Charlene Bollinger, Sherri Tenpenny, Rizza Islam, Rashid Buttar, Erin Elizabeth, Sayer Ji, Kelly Brogan, Christiane Northrup, Ben Tapper, and Kevin Jenkins.

The researchers say these influential accounts have large numbers of followers and produce high volumes of anti-vaccine content.

Many people on social media who end up sharing anti-vaccine content wouldn't necessarily follow any of these accounts themselves, but the new analysis suggests the majority of shared anti-vaccine posts on platforms like Facebook and Twitter originally begin with this relatively small group of actors.

The group's influence varies depending on the social platform, featuring in up to 17 percent of anti-vaccine tweets on Twitter, but up to 73 percent of anti-vaccine content on Facebook, the report suggests.

The research, originally released in March, was published to urge the leaders of social media platforms to 'deplatform' these prominent voices, whose airing and sharing of anti-vaccine conspiracies and hoaxes ultimately costs lives.

"Disinformation has become a direct threat to public health," Ahmed said in March.

"Social media is enabling anti-vaxxers to recruit millions of Americans and indoctrinate them with fear and doubt. If Big Tech companies don't act now, the pandemic will be prolonged, and more lives will be lost."

Despite a wave of political pressure to take action against the identified dozen accounts, a follow-up study published by CCDH and Anti-Vax Watch in April found 10 of the group were still on Facebook and Twitter as of April 25, with nine remaining on Instagram.

In the weeks since then, some accounts have been banned or restricted, but others have been left alone, retaining their ability to spread misinformation, exposure to which has been linked to higher rates of vaccine hesitancy.

According to the researchers, it's a dangerous failure by tech companies to properly and responsibly rein in the spread of reckless falsehoods on social platforms – many of which are spearheaded by a canny and highly organized body of profit-seeking entrepreneurs.

"The key protagonists in the 'anti-vaxx industry' are a coherent group of professional propagandists," Ahmed wrote in an article in Nature Medicine earlier in the year.

"These are people running multi-million-dollar organizations, incorporated mainly in the USA, with as many as 60 staff each. They produce training manuals for activists, tailor their messages for different audiences, and arrange meetings akin to annual trades conferences, like any other industry."

The report is available on the CCDH website, as is the follow-up analysis.