Covid19, vaccines and blood clots

DR MAXWELL ADEYEMI

Reports of people developing blood clot after receiving certain brands of covid19 vaccines has continued to make the headlines. So far, few people have developed blood clots after receiving the AstraZeneca and Johnson & Johnson vaccines, leading to the temporary suspension or limited use in some countries.

Recently, more people have been talking about the link between the AstraZeneca vaccine and a rare blood clot in the brain. While some countries have halted the use of these vaccines, some jurisdictions have continued to administer them. The general understanding so far is that the benefits of the AstraZeneca vaccine in protecting against the coronavirus outweigh any risks.

Covid19 infection can also cause blood clots. These clots are owing to widespread inflammation that takes place in the endothelial cell that lines inner surfaces of the blood vessels, especially as the patient becomes critically ill. Close to 20 per cent of covid19 patients develop blood clots while about 0.4 per cent of those who take the vaccine may develop clots. Therefore, the fear of blood clots should not prevent anyone from taking vaccines on offer in their respective countries.

Don’t let fear of blood clots deter you from getting any vaccinated against covid19.

A blood clot is a gel-like clump of blood. Clots form whenever the skin is cut to plug the injured area and stop the bleeding. When clots are formed within a blood vessel they can be very dangerous, as they can block blood flow. These clots typically occur in people who are bedridden, hospitalised, or have medical issues related to inflammation, infection or cancer. Inactivity, long flights, smoking, and obesity can also predispose people to clots.

Clots can form for a number of reasons, including medication, lifestyle factors and other health conditions, and they can occur in different parts of the body. Medications like birth control pills and some HIV treatments list blood clots as a potential side effect. Conditions like autoimmune disorders, pregnancy and cancer have also been associated with clotting. There are several different variations of blood clots, each with its own set of concerns and options for treatment.

Blood clots can cause severe harm or be fatal if left unaddressed, and they can originate in the veins or arteries. There are two main types of blood clots to be aware of, each leading to its own set of potential complications. One type is called a thrombus, which is a stationary clot. These block blood flow in the part of the body where the clot occurs. The other type, called an embolus, is a blood clot that can break loose. These are particularly dangerous because they can travel to other parts of the body like the heart or the lungs and cause severe damage.

The symptoms of blood clots vary, depending on the type. When the clot is stationary, like deep vein thrombosis (a clot in the leg), you may experience warmth and redness where the clot is located, typically in the leg or the arm, swelling, pain near the site of the clot, numbness or weakness, a change in your mental state. If the clot has travelled, leading to complications like a pulmonary embolism (a clot that has moved to the lungs), you may experience symptoms such as sudden shortness of breath, a cough with or without blood, clammy, pale or blue skin, excessive sweating, anxiety, weakness, nausea or vomiting.

The type of clot that occur in covid19 vaccines is a particularly rare one that often occurs in the brain and is known as cerebral venus sinus thrombus (CVST) because it occurs in the venous sinuses of the brain.

These blood clots are peculiar to AstraZeneca, Johnson and Johnson, and Sputnik V vaccines, all of which are viral vector vaccines that use a harmless inactivated common adenovirus (which causes cold and other illness when active) as a sort of Trojan Horse that carries the genetic code of the SARS-Cov-2 spike protein to a vaccine recipient’s cell. The code then instructs the cells to produce a spike protein that trains the bodies immune system.

Another unusual feature of the clots developed after vaccination is that these vaccine recipients also develop low platelets (thrombocytopenia). This is unusual in someone with a major blood clot because platelets are blood cells that have the function of helping blood clots. So with low platelets, one expects bleeding as opposed to blood clots.

Symptoms of vaccine-induced clotting include:

• Severe abdominal pain or headache commencing four to 20 days after receiving the vaccine

• A persistent headache unresponsive to Paracetamol

• A general feeling of systemic unwellness beyond four days after the vaccination

• Stroke-like symptoms, seizures or vomiting.

• Dizziness

• Transient loss of speech or balance

• Weakness on one side of the body

• Confusion

• Blurred vision.

• Leg pains

• Shortness of breath.

Seek immediate medical help if you develop any of these symptoms. Contact Dr Maxwell on 363-1807 or 757-5411.