AstraZeneca's (NASDAQ: AZN) coronavirus vaccine ran into another public safety controversy this week, with Europe's medicines regulator discovering a possible link between the vaccine and rare blood clots. However, the regulator still recommends the shot's use as the benefits of the vaccine outweighs the risk.
The European Medicines Agency (EMA) concluded on Wednesday that unusual blood clots with low blood platelets should be listed as a very rare side effect on Vaxzevria's (the vaccine developed by Oxford University in partnership with AstraZeneca) product information.
The regulator determined that the risk of this very rare side effect occurs within 2 weeks of vaccination, with data showing that most reported cases were women under 60 years of age. Based on current evidence, specific risk factors have not been confirmed.
The EMA noted that the blood clots affected the veins in the brain,--cerebral venous sinus thrombosis (CVST)--in the abdomen--splanchnic vein thrombosis (SVT)--and in the arteries, with symptoms also leading to low levels of blood platelets and possible bleeding. Researchers have documented 62 cases of CVST and 24 cases of SVT as of March 22, with 18 being fatal.
While researchers do not know what specifically links the vaccine to these blood clots, one plausible explanation is that Vaxzevria causes an immune response in some patients similar to the one observed in patients treated with heparin, which is called heparin induced thrombocytopenia, officials said.
This new controversy has lead many government to advise against younger people receiving Vaxzevria, with the United Kingdom recommending people under 30 to choose a different shot. The vaccine has already gathered plenty of public safety concerns and other empty promises, including its halted clinical trials, failing to meet supply deadlines, using outdated trial data for regulatory approval, and even threatening to block vaccine made of bottled in the European Union from being exported to other countries.
Vaxzevria is one of four vaccines approved for use in the E.U., with others including the Pfizer (NYSE: PFE)-BioNTech (NASDAQ: BNTX), Moderna (NASDAQ: MRNA) and Johnson & Johnson (NYSE: JNJ) vaccines.