Bleeding and clotting cases after the COVID-19 vaccination in India are "minuscule" and in line with the expected number of diagnoses of these conditions in the country, a report submitted by the national AEFI (adverse event following immunisation) committee to the health ministry has said. "Covishield continues to have a definite positive benefit-risk profile with tremendous potential to prevent infections and reduce deaths due to COVID-19 across the world and in India," the health ministry has said.
The study was conducted after alerts raised in some countries on post-vaccination "embolic and thrombotic events" on March 11, particularly with the AstraZeneca-Oxford vaccine, which is named Covishield in India. The Centre conducted an analysis of the adverse events in India and that only 0.61 cases of blood clotting per million were reported in its analysis.
As per the National AEFI committee findings, as of April 3, around 75,435,381 vaccine doses had been administered (Covishield - 68,650,819; Covaxin - 6,784,562). Of these, 65,944,106 were first doses and 9,491,275 second doses. Since the COVID-19 vaccination drive was initiated -- more than 23,000 adverse events were reported through the COWIN platform. Of these, only 700 cases -- 9.3 cases per million doses administered -- were reported to be "serious and severe in nature".
"The AEFI committee has completed an in-depth case review of 498 serious and severe events, of which 26 cases have been reported to be potential thromboembolic (formation of a clot in a blood vessel that might also break loose and carried by the bloodstream to plug another vessel) events - following the administration of Covishield vaccine - with a reporting rate of 0.61 cases/ million doses," the statement said.
No potential thromboembolic events were reported after the administration of the Covaxin vaccine. "There is a very miniscule but definitive risk of thromboembolic events. The reporting rate of these events in India is around 0.61/million doses, which is much lower than the 4 cases per cent per million reported by UK's regulator Medical and Health Regulatory Authority (MHRA). Germany has reported 10 events per million doses," it added.
Notably, thromboembolic events keep occurring in the general population as background and scientific literature suggests that this risk is almost 70 per cent less in persons of South and South-East Asian descent in comparison to those of European descent. As per the health ministry, healthcare workers have been advised to encourage people to be aware of suspected thromboembolic symptoms occurring in 20 days after receiving any COVID-19 vaccine, particularly Covishield.
Symptoms of blood clotting after vaccination:
- Pain in chest
- Pain in limbs/pain on pressing limbs or swelling in limbs (arm or calf)
- Multiple, pinhead size red spots or bruising of skin in an area beyond the injection site
- Persistent abdominal pain with or without vomiting
- Seizures in the absence of the previous history of seizures with or without vomiting
- Severe and persistent headache with or without vomiting (in the absence of the previous history of migraine or chronic headache)
- Weakness/paralysis of limbs or any particular side or part of the body (including face)
- Persistent vomiting without any obvious reason
- Blurred vision or pain in eyes or having double vision
- Change in mental status or having confusion or depressed level of consciousness
- Any other symptom or health condition which is of concern to the recipient of the family