Clotting, bleeding cases after jab minuscule: Govt
India has reported clotting and bleeding events in just 0.61 for every million doses of the Covishield vaccine administered to people, the Union health ministry said on Monday, citing a report submitted by the national adverse events following immunisation (AEFI) committee that highlights the safety of the most widely used vaccine in the country.
The assessment was based on the analysis of 498 serious AEFIs reported as on April 3 -- by then, 75 million doses had been administered in all. Concerns over the risk of blood clots relate to one of the two vaccines used in India -- Covishield, which is the Indian version of the Oxford-AstraZeneca vaccine -- after several western countries began noticing cases .
The data from India now shows it was seen only in 26 of the 498 AEFIs. “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 blood stream to plug another vessel) events – following the administration of Covishield vaccine – with a reporting rate of 0.61 cases/ million doses,” read the health ministry’s formal statement.
Officials recorded close to 700 AEFIs in all from among the 75 million doses till April 3, but had detailed data for only 498. “Therefore, the denominator also had to be adjusted, and the number of Covishield and Covaxin doses was proportionally reduced,” said Dr NK Arora, who chairs the National AEFI committee.
Going by this calculation, the AEFI assessment was likely to have been based on a little over 42 million doses administered till that time.
“AEFI data in India showed that there is a very minuscule 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 million reported by UK’s regulator Medical and Health Regulatory Authority. Germany has reported 10 events per million doses,” the statement added.
Serum Institute of India (SII) locally manufacturers Oxford-AstraZeneca’s Covid-19 vaccine under the brand name Covishield, which is one of the two vaccines currently being used under national Covid-19 immunisation programme. The other is Covaxin, made by Bharat Biotech.
Alerts were raised in some countries on post-vaccination ‘embolic and thrombotic events’ on March 11, particularly with the Oxford-AstraZeneca vaccine.
In the aftermath, India decided to conduct an in-depth analysis of the adverse events (AE). “Bleeding and clotting cases following 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 Immunization) Committee to the Ministry of Health & Family Welfare said,” read the statement.
The clotting reports initially were seen to have triggered some vaccine hesitancy, although India now has a demand that is in excess of supply.
There were no such potential clotting or bleeding event reported among those who were administered Covaxin doses.
The national AEFI committee noted that as on April 3, 2021, at least 75 million (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 were given as the second dose.
Since the Covid-19 vaccination drive was initiated on January 16, 2021, at least 23,000 adverse events were reported through the Co-WIN platform from 684 of the 753 districts of the country. Of these, only 700 cases— at the rate of 9.3 cases per million doses administered— were reported to be serious and severe in nature, according to the report.
The report also says that the thromboembolic events keep occurring in general population as background and scientific literature suggests that this risk is almost 70% less in persons of South and South East Asian descent in comparison to those from European descent. Data on the incidence in the clots in the general population was not provided by the ministry.
The ministry of health is separately issuing advisories to healthcare workers and vaccine beneficiaries to encourage people to be aware of suspected thromboembolic symptoms occurring within 20 days after receiving any Covid-19 vaccine (particularly Covishield), and report to the health facility where vaccine was administered.
Among symptoms that need to be watched out for are breathlessness; chest pain, pain in limbs or 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 previous history of seizures with or without vomiting; severe and persistent headache with or without vomiting (in the absence of previous history of migraine or chronic headache); weakness or 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; and change in mental status or having confusion or depressed level of consciousness.
The list also includes any other symptom or health condition which is of concern to the recipient or the family.
At least 164.6 million doses of Covishield was administered as on May 17, 2021, the Co-WIN dashboard showed on Monday.
“Health ministry is continuously monitoring the safety of all Covid-19 vaccines and is promoting reporting of suspected adverse events. Covishield, the Covid-19 vaccine, 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 ministry statement read.
“Vaccination is the most potent weapon to fight the pandemic. The vaccines are safe, and should be taken by everyone unless contraindicated,” said Dr GC Khilnani, former head, pulmonology department, All India Institute of Medical Sciences, Delhi.