Covishield & Blood Clots: Do we need to worry about this?

by Shoubhik Sen

Since the beginning of the vaccination drive, there have been reports of blood clotting. This is specially true in the case of Oxford-AstraZeneca’s COVISHIELD vaccine. In fact, many European nations have stopped administering this vaccine. They suspect a link between this and the blood clots that follow.

Considering the fact that Covishield is the primary vaccine being administered to Indians, this reveal does raise some concerns. Thus today, we shall see if there’s a link between Covishield and Blood Clots or not.

Symptoms: When to Gauge that you have Clots

You can stop yourself from suffering, or at least, reduce it as much as possible. It’s here that you need to look out for the following symptoms: –

  • Severe headache such that even regular painkillers don’t work.
  • Momentary increase in the headaches when lying or bending over.
  • Blurred vision
  • Nausea
  • Vommiting
  • Speech Difficulties
  • Weakness or Drowsiness
  • Seizures
  • New and unexplained Pinprick bruising or bleeding
  • Shortness of Breath
  • Chest Pain and Persistent Abdominal Pain
  • Swelling of the Leg
nausea vomiting

These are the symptoms of clotting. Moreover, PUBLIC HEALTH ENGLAND too published their report in which similar symptoms were shown for clotting. Rush to your nearest health professional if you see or feel any of these symptoms.

Europe’s worries over Covishield

European nations are mainly concerned about the internal bleeding that accompanies the blood clots, after taking Covishield/Vaxzevria. Otherwise ordinary blood clots are easy to treat.

Scientists call this condition Vaccine-induced Immune Thrombotic Thrombocytopenia (VITT). Though less, but a number of people experienced Blood clotting and Internal Bleeding after taking AstraZeneca’s Covishield. Out of all the clots in the body, the deadliest is the one occurring in the brain. Scientists call it Cerebral Venous Thrombosis (CVT) or Cerebral Venous Sinus Thrombosis (CVST).

blood clots

The European Economic Area alone saw 164 CVT Cases after 34 million vaccinations. That means roughly 5 out of every million AstraZeneca recipients developed this condition. Furthermore if we talk about the UK, the number goes up to 20 million people. That’s roughly the population of Mumbai. Moreover, 19 recipients even died of VITT. Additionally, there were even deaths due to the overall clotting/bleeding problem of CVT.

Women at Greater risk??

Initially, most of the victims of this condition were women, which led to believing that they are at greater risk. However, many later studies disproved this hypothesis.

The number of women employed in the healthcare sector is more than that of men. Moreover, the doses were administered to health workers before anyone else. Thus, this was the reason that ore women reported the VITT/CVT problem.

In women, blood clotting is also one of the reactions after taking contraceptive pills. In fact, 1 out of every 1,000 women experience this. Thus, we’re not sure if the clotting happened in women due to Covishield or due to contraceptives.

However, if we go by some studies in the U.K, this might not be the case and instead, the vaccine actually is causing all of it.

The mechanisms behind the type of clotting linked to the vaccine and that linked to the pill appear quite different.

Prof. Adam Taylor (Lancaster University)

Thus, it’s better if we DON’T believe the theories linking contraceptives, pregnancy and hormonal replacement therapies to clots occurring after vaccination.

Is Covishield really the cause??

As seen above, there are theories floating around that are equally strong on both sides. However, international agencies are leaning more towards the view that Covishield actually does lead to blood clots. On the other hand, there’s no clear evidence of this claim.

The European Medicines Agency has said that VITT should be listed as a “very rare side effect” of the vaccine. On the other hand though, British authorities still prefer more work on this. However, they too believe that the evidence supporting the link is strong.


The W.H.O feels that there’s just a casual relationship between the vaccine and VITT. However, it also claimed that said relationship maybe “plausible” but it’s not “confirmed“. It derives its claims from the data of 190 million AstraZeneca vaccinations.

However, our focus should be on the alternatives we have at hand. Indians do not have the luxury to choose from a number of vaccine manufacturers. Instead, Covishield is the mainstay for our entire vaccination drive. So on one hand we have this vaccine and on the other, a chance to get infected by Covid. In fact, new data shows that Covid causes far more harm than the vaccine. Moreover, an Oxford study published recently, claims that the risk of CVT from Covid is 8 times greater than the risk from Covishield.

Thus, the best step currently is to get your dosage as soon as possible. If at all you get VITT/CVT, the symptoms will appear between 4 days to 4 weeks after your 1st shot. However in a situation like this, rush to your nearest doctor “urgently”.

Get More Covid Updates