A nurse displays a vial of AstraZeneca's COVISHIELD vaccine.
Credit: Reuters Photo
There is a harsh focus on the working of vaccines, much after many vaccines helped to save millions of lives during the Covid pandemic. The vaccine developed by pharmaceutical company AstraZeneca has been at the centre of a controversy after the company admitted that its vaccine, Covishield, can in very rare cases cause a side effect associated with blood clotting. Covishield was the most widely used Covid vaccine in India.
The company now withdrawn the vaccine globally citing “industrial reasons” and “due to a surplus of available vaccines”. The company has faced cases in courts over the side effect known as thrombosis with thrombocytopenia (TTS). In India, the vaccine has not been produced for about two years by the manufacturer the Serum Institute of India, Pune. No cases of side effects, as reported from other countries, has been reported from India.
It is known that vaccines, and generally all medicines, have side effects. In the case of Covid vaccines, and specifically for the AstraZeneca vaccine, it is not a new revelation. The product information on Covishield had mentioned TTS as a possible side effect. Virologists have pointed out that all the rare risks of a vaccine cannot be found out in the trial stage. A risk of one in one lakh or two lakh cannot be found out without luck in trials involving 30,000 volunteers. Trials had to be done in a matter of months, against the norm of many years, in the case of Covid vaccines. The rare side effects are noticed only after the vaccines are administered on a large scale. That is what has happened in the case of the AstraZeneca vaccine. All this may not clear the company of its legal and moral liability for the side effects of the vaccine. The issue may have to be judged by the courts.
There should be an evaluation of risks and benefits in the case of all vaccines. In the case of Covid vaccines their benefits far outweighed the risks. The oral polio vaccine, which helped to eradicate polio from most of the world, has a one in 2.7 million risk of causing paralysis. The rare side effects should not be used to vilify all vaccines and strengthen vaccine resistance which exists in most parts of the world, including India. That would be a huge setback to public health and its administration. The Supreme Court has agreed to hear a petition seeking the setting up of an expert panel to investigate the side effects of Covid vaccines. It is important to have reliable information on such vital matters of public health.