Facebook said Tuesday that it pulled down 308 fake accounts, including from Instagram, that pushed disinformation about the AstraZeneca and Pfizer COVID-19 vaccines.

The social network has been under pressure from US politicians and regulators to do more to combat false claims about the COVID-19 vaccines. Although the social network works with fact-checkers to label content and direct people to a hub of coronavirus information, advocates groups and other critics point out that misinformation continues to spread about the vaccine on the network and its photo application, Instagram.

Facebook said it removed the fake accounts in July for violating its rules against foreign interference and for misleading others about the purpose of the accounts and the identity of those behind them. According to the social network, the accounts were created in Russia. Fazze, a UK-registered marketer firm, was also banned from its platform. CNET could not immediately reach Fazze. Facebook stated that the accounts were targeted at people in Latin America, India, and the US, but they didn’t reach a large audience.

The accounts falsely claimed that AstraZeneca would make people chimpanzees in November and December 2020. Facebook stated that the accounts also posted misleading posts and petitions on other sites such as Change.org and Medium. The petitions and blog posts were written in English and Hindi. They claimed that AstraZeneca had manipulated COVID-19 vaccine trial data, and used an unknown technology to create the vaccine. These accounts created memes that claimed the vaccine would make people chimpanzees, and paired petitions and blogs with hashtags suggesting that the vaccine was dangerous. Facebook claimed that it is likely that the operation requested health and well-being experts to share their content in order to spread their campaign against AstraZeneca.

Facebook stated that the fake accounts stopped posting after May 2021. The fake accounts then promoted content claiming that Pfizer’s COVID-19 vaccine had a higher “casualty ratio” than other vaccines. They cited a 12-page document claimed to have been hacked from AstraZeneca. The BBC reported in July that Fazze was recruiting influencers, including on Google-owned YouTube, to spread disinformation about COVID-19 vaccines, and the news outlet noted that the “data the influencers were asked to share had actually been cobbled together from different sources and taken out of context.” The BBC pointed out that just because someone dies from the vaccine does not mean they were the cause.

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Both campaigns occurred at the same time as governments were discussing emergency authorizations for AstraZeneca vaccines and Pfizer vaccines. Facebook acknowledged that there is still much to learn, including the identity of Fazze, who was commissioned by Facebook to conduct the disinformation campaign.