NEW DELHI: A study of adverse events from more than 75 million vaccine doses administered till 3 April showed that there was a 0.61 per million chance of vaccinees getting a serious case of blood clots after getting Serum Institute of India’s Covishield, which a government panel said constituted a “very miniscule but definitive risk”.
The government panel assessment was based on a review of 26 cases post-vaccination of potential thromboembolic events—formation of a clot in a blood vessel that might break loose and carried by the blood stream to plug another vessel.
“There were no potential thromboembolic events reported following administration of Covaxin vaccine,” the health ministry said in a statement on Monday, after a government committee reviewed 23,000 cases of adverse events following immunisation (AEFI).
The National AEFI Committee found that out of the 23,000 cases, 700 were serious or severe, which makes it a 9.3 per million chance, and 26 of them were potential thromboembolic events.
The rate of 0.61 per million in India, however, is much lower than the 4 cases per million reported by UK Medical and Health Regulatory Authority, and 10 events per million doses reported in Germany, the government said.
The events, which are extremely rare, can cause damage, especially when it is in combination with thrombocytopenia. In Europe, seven cases of blood clots in multiple blood vessels and another 18 cases of cerebral venous sinus thrombosis (CVST)—where blood clots are formed in the brain—have been reported after more than 20 million vaccinations, making the chances of these extremely rare yet significant. Nine of the 25 people died.
The European Medicines Agency (EMA) had in March said that the vaccine may be associated with very rare cases of blood clots associated with thrombocytopenia, a condition where there are low level of platelets that help the blood clot. However, despite the findings, the EMA said that the benefits of the vaccine in combating the covid-19 continue to outweigh the risk of side effects.
After the EMA’s announcement, India took the decision to conduct an urgent in-depth analysis of the adverse events.
The health ministry said it is separately issuing advisories to healthcare workers and vaccine beneficiaries to make people aware of suspected thromboembolic symptoms, which can usually occur within 20 days after receiving any covid-19 vaccine, particularly Covishield, and report it preferably to the health facility where vaccine was administered.
The signs that the ministry has asked people to watch out for after receiving the vaccine are breathlessness, pain in chest or in limbs, when pressing limbs, limbs/pain on pressing limbs or swelling in limbs, seizures, severe and persistent headache, blurred vision or pain in eyes, change in mental status, among others.
The health ministry reiterated what the EMA and World Health Organization had said in March, that Covishield continues to have a positive benefit due to its “tremendous potential to prevent infections and reduce deaths due to covid-19 across the world and in India”.
Never miss a story! Stay connected and informed with Mint.
our App Now!!