Four websites featuring articles that cast doubt about the COVID-19 vaccines have been traced back to Russian intelligence agencies as part of their alleged campaign to diminish confidence in the drug’s efficacy and safety, the Wall Street Journal reports

An official with the U.S. Department of State’s Global Engagement Center found that these online publications, which have been identified as New Eastern Outlook, Oriental Review, News Front, and Rebel Inside, are spreading false or misleading information about the side effects of the Pfizer vaccine and the United States’ role in attempting to rush its approval by Food and Drug Administration. While the readership on these sites is quite low, there’s concern that these articles could garner more attention if they were to be picked up and circulated by international outlets. 

According to the CDC, the possible common side effects associated with the COVID-19 vaccine include redness, swelling, and pain on the arm where you received the shot, as well as tiredness, headaches, muscle pain, fever, chills, and nausea. If these issues persist for more than a few days, then you must contact a doctor. 

In December, FDA commissioner Dr. Stephen Hahn pushed back against Donald Trump’s pressure to speed up the approval process for the Pfizer vaccine, saying he was going to take the necessary amount of time to “get this right.” The push for approval was spearheaded by Trump, who was suspected to be using the vaccine’s availability as a means for re-election.

The Johnson & Johnson vaccine, which was announced just last month, took longer than its predecessors, Moderna and Pfizer, but offers some notable improvements that could be attributed to being given more time to make certain tweaks. Unlike the previous two, J&J’s vaccine only requires a single dose, and doesn’t need to be stored in a freezer at an insanely cold temperature.