Do mRNA vaccines against COVID-19 create blood clots, which lead to thrombosis? No, that's not true: mRNA COVID vaccines have not been linked by scientific evidence to causing blood clots.
The claim appeared in videos such as this one (archived here), published on TikTok in May 2023. It shows Romanian politician and member of the European Parliament Cristian Terheș speaking about COVID vaccines in a video podcast.
This is what the post looked like at the time of writing:
(Source: TikTok screenshot taken on Thu Jun 8 14:39:52 2023 UTC)
Terheș makes several false claims and suggestions based on scientifically unsupported claims on COVID vaccines that have been frequently fact checked by Lead Stories. He says that all people who got the Moderna or Pfizer vaccine should do a specific test to check themselves for blood clots, which are caused by mRNA COVID vaccines.
But blood clots (which, if blocking blood vessels, lead to thrombosis) have not been linked to either of the mRNA vaccines from Pfizer/BioNTech or Moderna. Only the Johnson & Johnson vaccine against COVID can cause a very particular kind of clotting that is extremely rare. Evidence suggests COVID vaccination prevents blood clots by protecting against COVID, which raises the risk of clotting.
