Health ministry releases list of blood clot symptoms to watch out for after taking Covishield

India — The Union health ministry said on Monday that the number of blood clot cases in people who received AstraZeneca’s Covid-19 vaccine (called Covishield) in India was “minuscule”. Covishield – one of three shots granted emergency approval in India – is the most widely used in the country and is manufactured by Pune-based Serum Institute (SII).

“AEFI (Adverse Event Following Immunisation) data in India showed that there is a very miniscule but definitive risk of thromboembolic events,” the health ministry said in a statement, citing a report by the National AEFI Committee.

Thromboembolic events refer to the formation of a clot in a blood vessel that might also break loose and be carried by the bloodstream to plug another vessel.

The ministry separately released advisories to healthcare workers and vaccine beneficiaries to encourage people to be aware of suspected thromboembolic symptoms. These symptoms, the ministry said, occur within 20 days of taking a shot (particularly Covishield) and asked the beneficiaries to report to the health facility where vaccine was administered.

The list of symptoms mentioned in the ministry’s advisory are:

According to the AEFI Committee, it 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 per million doses.