Concerns about the safety of Covid vaccines have returned with pharmaceutical giant AstraZeneca admitting that its vaccine, developed in collaboration with Oxford University, can have a rare but serious side effect. This has raised an alarm in India as it is the same vaccine, manufactured by Serum Institute of India and branded as Covishield, that was administered to a majority of the country’s population; about 175 crore doses of the vaccine were administered. The side effect, called thrombosis with thrombocytopenia syndrome (TTS) in medical literature, is characterised by blood clots and low platelet counts. The first cases of TTS came to light in the early months of vaccination in Europe.
In India, the Government Committee on Adverse Events Following Immunisation is said to have investigated 36 cases of TTS and confirmed 18 deaths in 2021, but it is not clear which vaccine they were linked to. Experts say the admission by AstraZeneca, though serious, need not cause panic as it’s a rare side effect, rarer still among Asians and South Americans. Besides, they say the risk is high only during the early weeks after vaccination. A study found 8.1 TTS cases per million people vaccinated after the first dose, and 2.3 cases per million after the second dose. It also showed there was a geographical variation in the risk—from 17.6 per million in the Nordic countries to 0.2 per million in Asia.
A petition has now been filed in the Supreme Court, citing an apparent increase in deaths due to heart attack and sudden collapse after Covid, even among youngsters; the petitioners seek the constitution of an expert panel to study the risks involving the vaccine. Concerns about Covid vaccines are not new and can be traced back to their emergency approval waiving the traditional trial protocols.
While the government acted with the aim of tackling an urgent health crisis, it now has the responsibility of addressing the consequences. All stakeholders involved in the development, distribution and monitoring of vaccines are answerable. While vaccination has saved lives and its benefits outweigh the risks, it’s important to reassure people about the reliability of the vaccine that was administered to about 90 percent of the adult population. There must be a thorough study in the interest of ensuring accountability and public safety.