3 doses of AstraZeneca Covid-19 vaccine, is there a risk of blood clots?

Dr. Nguyen Hong Vu, City of Hope Research Institute (California, USA), advises:

You don’t need to worry about side effects from the AstraZeneca Covid-19 vaccine. The rate of blood clots when receiving this vaccine is only 2/100,000 people, equivalent to 0.002% for people 60 years of age and older. This rate in people under 60 years of age is equivalent to 2-3/100,000 people.

Meanwhile, the rate of blood clots in people with Covid-19 is about 6-26% in the veins and about 0.7-3.7% in the arteries, which is higher when you get vaccinated. Comparing the risk of Covid-19 with the side effects of the vaccine, people still recommend taking the vaccine. People who got vaccinated 2-3 years ago do not need to worry.

If you are afraid of blood clots forming in your body, you should remember that the following other factors are even more dangerous: atherosclerosis, heart disease (atrial fibrillation, heart failure, heart valve disease), diabetes, cancer, obesity, high cholesterol, pregnant women, sitting too long or lying in bed continuously, smoking, family history of blood clots. To avoid the risk of blood clots, you should eat scientifically and exercise regularly.

Dr. Nguyen Thu Anh, Director of Woolcock Medical Research Institute Vietnam, further advises:

Blood clots occur within 2 weeks of receiving the AstraZeneca Covid-19 vaccine. This is a very rare side effect. The mechanism that causes blood clots due to vaccination (a vaccine made from adenovirus) will activate platelets (a type of blood cell), platelets release PF4, a type of protein. In some people, the vaccine particles and PF4 have opposite charges, so they attract each other to form clumps, thereby causing blood clots. After the vaccine particles are gone, the platelets return to normal, without PF4 there is no longer a risk of blood clots.

Blood clots are not only seen after receiving the AstraZeneca vaccine, people with Covid-19 can also experience this condition. In fact, it has been found that this risk can occur up to 6 months after infection.

Therefore, the community should not worry about stroke due to blood clots. You should have a general health check-up to determine whether your body has high blood pressure, diabetes, or high blood fat. At the same time, create good habits such as exercise, quit smoking, and alcohol. Learn about stroke symptoms and first aid so that if a stroke occurs, you can go to the hospital early.