Blood clots are an extremely rare but serious side effect of AstraZeneca’s COVID-19 vaccine, regulators announced Wednesday.
The benefits of the AstraZeneca vaccine still outweigh the risks, the European Medicines Agency (EMA) said in a press release. Still, the agency’s safety committee said it’s important to know the signs of a possible clot.
A blood clot occurs when the blood thickens and forms a semi-solid mass. It can be a helpful response to stop bleeding in the event of an injury, but these blockages can cause problems if they cut off blood flow to a vital area.
Blood clots can cause blockages in the legs, abdomen and lungs. Most blood clots associated with the AstraZeneca vaccine have occurred in veins in human brains.
These clots, known as cerebral sinus vein thrombosis (CVST), can lead to stroke, seizures, and death.
So far, most of the reported clots have occurred in women under 60 years of age within two weeks of vaccination.
Since young people are more likely to have this side effect, UK vaccine regulators recommend that people under 30 do not receive an AstraZeneca injection unless they have already received their first dose.
Symptoms of blood clots include shortness of breath and headaches
The EMA said patients who have received the AstraZeneca vaccine should seek immediate medical attention if they have the following symptoms:
- shortness of breath
- chestpain
- swelling in your leg
- persistent stomach pain
- neurological symptoms, including severe and persistent headache or blurred vision
Some mild side effects, such as injection site pain or other body aches, are common in the days following vaccination.
But if you experience severe or persistent symptoms about four to 20 days after vaccination, you should seek medical attention, according to the World Health Organization.
Blood clots are usually treated with anticoagulants. Complications can be prevented if the clot is caught early.
This article was originally published by Business Insider.
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