COVID-19 Vaccination: Should I Be Worried About Blood Clots?

Why Are People Worried?

There has been concern and scrutiny of the AstraZeneca (AZ) COVID-19 vaccine on the issue of the very rare clots, with a higher incidence in younger people. The vaccine is widely used in the United Kingdom (UK) but several countries have paused the distribution and administration of the vaccine due to the safety concerns. 

Both the European Medicines Agency (EMA) and UK Medicines and Healthcare products Regulatory Agency (MHRA) have published reports confirming the possible link between the clots and the vaccine but stressed the clotting disorder is  uncommon and that the benefits of the vaccine still outweigh its risks.¹

What Kind of Blood Clots Are Associated With The AZ COVID-19 Vaccine?

The clots that have been tentatively associated with the AstraZeneca COVID-19 vaccine have particular characteristics: they occur in unusual parts of the body, such as the brain or abdomen, and are coupled with low levels of platelets – cell fragments that aid blood coagulation. The most severe is CVST which stands for cerebral venous sinus thrombosis.⁵ This is a clot found in a large vein in the brain. Blood normally travels through veins from the brain back to the heart. The CVST clot can block the flow of blood in the brain, reducing oxygen supply and potentially causing damage – stopping the central nervous system from working properly.  

How Common Is Blood Clots In The AZ COVID-19 Vaccine?

As mentioned, the incidence of the AstraZeneca COVID-19 vaccine related clot is rare. Based on the latest data reported by MHRA, the risk of clot after the vaccine is estimated to be 4 in a million.² Conversely the risk of a clot upon diagnosis of COVID-19 is far greater at 30 in a million.³To properly understand the risks of taking the vaccine, it is important to also recognise its benefits. The AstraZeneca COVID-19 vaccine  has been proven to provide close to  100% protection against hospitalisation, severe disease and death from COVID-19, and therefore also against the blood clots those with the virus are at risk of experiencing.⁶

What Should I Watch Out For?

Recently, 260k individuals in Malaysia have signed up voluntarily for the AstraZeneca COVID-19 vaccine. Even though the risk of clot is very low, it is important for those signed up for the vaccine to be aware of the symptoms so they can get prompt medical treatment if necessary. These symptoms include: breathlessness; pain in the chest or stomach; swelling or coldness in a leg; severe or persistent headaches or blurred vision; or tiny blood spots under the skin beyond the site of the injection.⁴ An urgent medical attention is needed if  any of these symptoms appears within 2 days to 4 weeks after the injection.

The Benefits Outweigh The Risk

The AstraZeneca COVID-19 vaccine is associated with the risk of clot such as CVST but current data shows the incidence is rare. However expert opinions have maintained that the benefits of the vaccine still outweigh the risks especially in countries where the pandemic is still raging out of control. 

Lastly, for any further clarification, do speak to your healthcare provider  to find out more on the subject matter or do approach or contact the pharmacist at any CARING Pharmacy stores or message us on our Facebook page.