Alerts were raised in some countries on post-vaccination "embolic and thrombotic events" on March 11 this year, particularly with the AstraZeneca-Oxford vaccine (Covishield in India), said the report.

 

A decision was taken to conduct an urgent in-depth analysis of the adverse events (AE) in India in the light of the global concerns.

 

The National AEFI Committee noted that as of April 3 this year, 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 from 684 of the 753 districts of the country.

 

Of these, the AEFI Committee said, only 700 cases (9.3 cases per million doses administered) were reported to be serious and of severe 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 get carried by the blood stream to plug another vessel) events -- following the administration of Covishield vaccine -- with a reporting rate of 0.61 cases per million doses.

 

"There were no potential thromboembolic events reported following the administration of Covaxin vaccine," the report said.

 

AEFI data in India showed that there is "very miniscule but definitive risk of thromboembolic events".

 

The reporting rate of these events in India is around 0.61 per million doses, which is much lower than the four cases per million reported by the UK's regulator Medical and Health Regulatory Authority (MHRA). Germany has reported 10 events per million doses.

 

Thromboembolic events keep occurring in 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 from Europe.

 

The Union Health Ministry 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 preferably to the health facility where the vaccine was administered.

 

Covishield continues to have a definite positive benefit risk profile with tremendous potential to prevent infections and reduce deaths due to the pandemic across the world and in India.

 

Over 13.4 crore doses of Covishield were administered as on April 27 this year in India. The Health Ministry is continuously monitoring the safety of all Covid-19 vaccines and is promoting reporting of suspected adverse events.