Amazon appears to be helping fund anti-vaccine not-for-profit organizations through its charity arm, the AmazonSmile Foundation, the Guardian can reveal.

The AmazonSmile fundraising program – through which Amazon donates 0.5% of the purchase price of a shopper’s Amazon transactions to an organization of their choice – is promoted on the websites of four prominent anti-vaccine organizations: National Vaccine Information Center (NVIC), Physicians for Informed Consent [see footnote], Learn the Risk, and Age of Autism.

Numerous other anti-vaccine organizations, including American Citizens for Health Choice (ACHC), National Health Freedom Coalition, Michigan for Vaccine Choice, Texans for Vaccine Freedom, A Voice for Choice and the Informed Consent Action Network are also listed by Amazon as eligible for the donations.

Amazon’s donations are just the latest example of how US tech companies have – wittingly or not – helped to promote and finance the anti-vaccine movement.

Facebook and YouTube have already faced criticism over the proliferation of anti-vaccine propaganda, which promotes false information casting doubt on the safety and efficacy of vaccines. Misinformation frequently outperforms science on the platforms, and self-serve advertising tools empower anti-vaxxers to target parents with fearmongering propaganda.

Not-for-profit organizations are key players in the anti-vaccine movement in the US. Groups such as the NVIC and ACHC advocate for legislation to allow parents to exempt their children from vaccination for non-medical reasons. Other groups promote messaging that calls into question the safety and efficacy of vaccines.

Age of Autism, for example, styles itself as the “daily web newspaper of the autism epidemic”. The site publishes a steady stream of content emphasizing the dangers of vaccination and promoting the discredited idea that autism is caused by “excessive vaccinations”. Each page on the site also includes a widget which reads, “Support Autism Age. When you shop at smile.amazon.com, Amazon donates.”

A widget on the Age of Autism site promotes shopping using AmazonSmile to fund the anti-vaccine organization. Photograph: Age of Autism

The AmazonSmile Foundation was launched in 2013 and has thus far donated nearly $125m to not-for-profit organizations. The Foundation’s funds come directly from Amazon, and Amazon customers can choose from one of more than one million eligible tax-exempt public charitable organizations.

The top recipients of AmazonSmile’s donations include well-known charities such as the St Jude Children’s Research Hospital, the Wounded Warrior Projects, the American Red Cross and Doctors Without Borders. But the program has also faced some criticism in the past over donations to the NRA Foundation and other gun rights organizations.

It is not clear how much money anti-vaccine organizations have received from AmazonSmile. The foundation’s financial disclosure for 2016 includes a 1,496-page spreadsheet of recipient organizations which is not machine readable and not in alphabetical order. In 2017, the most recent year for which the disclosures are available, AmazonSmile did not release an itemized list of disbursements.

The sums are probably small, however, as are the budgets of most of the anti-vaxx organizations. NVIC has among the largest budgets, with a 2017 revenue of $1.2m, but groups such as ACHC, Physicians for Informed Consent and Learn the Risk all have annual revenues of less than $100,000, according to tax filings.

Amazon did not directly comment on the donations to anti-vaccine organizations. A spokeswoman noted that groups that “engage in, support, encourage, or promote intolerance, hate, terrorism, violence, money laundering, or other illegal activities” are not eligible for AmazonSmile. The company follows recommendations from the US Office of Foreign Assets Control and the Southern Poverty Law Center to determine which groups are ineligible, the spokeswoman said.

Amazon is also helping to finance one prominent anti-vaxxer who does not operate through a not-for-profit: Larry Cook.

Cook has gained notoriety as the founder of Stop Mandatory Vaccination, a website, Facebook page and private Facebook group with more than 150,000 members. Cook has raised nearly $80,000 on GoFundMe since 2015. He also solicits donations on his website and market’s anti-vaccine T-shirts through Teespring. Until recently, Cook also earned money through his YouTube channel, which promoted anti-vaccine videos, but YouTube demonetized the channel following queries from BuzzFeed News.

Larry Cook began promoting his Amazon storefront after YouTube demonetized his videos. Photograph: Amazon

Following YouTube’s decision to demonetize Cook’s videos on 22 February, Cook began soliciting direct donations “to help offset this financial loss” inside the Stop Mandatory Vaccinations Facebook group. He also began aggressively promoting an Amazon “storefront” through which followers can purchase a selection of anti-vaccine books and DVDs, as well as nutritional supplements that he recommends.

The storefront is part of Amazon’s “influencer program”, which allows people with large social media followings to set up a store of recommended products and earn a cut if their followers make purchases. Cook’s Stop Mandatory Vaccination page includes a disclosure that SMV “earns money from this storefront”. Since 25 February, Cook has shared a link to the storefront to the private SMV group 17 times.

Amazon has also come under scrutiny for its role in providing a platform to anti-vaccine propaganda in recent weeks. Adam Schiff, chair of the House intelligence committee, wrote to Amazon’s chief executive, Jeff Bezos, on 1 March to express concern that “Amazon is surfacing and recommending products and content that discourage parents from vaccinating their children”. Schiff cited a report by CNN Business which found that Amazon search results for “vaccine” were dominated by anti-vaccine books and movies, including the disgraced former-physician Andrew Wakefield’s movie, VAXXED, which was available for streaming on Amazon’s Prime Video platform. Hours after Schiff’s letter was released, Amazon removed several anti-vaxx movies from Prime Video, BuzzFeed News reported.

• Footnote added on 11 March 2019: A lawyer for Physicians for Informed Consent (PIC) contacted the Guardian after publication to say that PIC does not consider itself to be an “anti-vaccine organization”, but rather is “ethically opposed to the coercion of vaccination”, including the mandatory vaccination of schoolchildren. To clarify, this article uses the term “anti-vaccine” to describe any group that “advocates for legislation to allow parents to exempt children from vaccination for non-medical reasons”, or “promotes messaging that calls into question the safety and efficacy of vaccines”. PIC is opposed to “vaccine mandates”, its lawyer noted, because PIC is “pro-informed consent”.