ASTRAZENECA (AZ), a leading pharmaceutical firm headquartered in the UK, has admitted that its Covid-19 vaccine can cause a side effect in 'very rare cases'. The disclosure came during the hearing of a case in the High Court of Justice in London. Fifty-one claimants have alleged that they — or their loved ones — suffered from TTS (thrombosis with thrombocytopenia syndrome) after receiving the AZ vaccine. This rare syndrome is characterised by blood clotting or abnormally low levels of platelets; its potentially life-threatening consequences include brain damage, heart attack, pulmonary embolism and amputation. The petitioners, who are seeking damages under the UK's Consumer Protection Act, reportedly possess documents substantiating their charge that the vaccine caused deaths or injuries.

The British case is of immense significance for India, where the AZ vaccine was manufactured and marketed as Covishield in partnership with the Pune-based Serum Institute of India. It was administered to almost 90 per cent of the eligible people in the country during the Covid years. Even though AZ has stated that patient safety is its highest priority, a thorough probe is required to allay the doubts and apprehensions of the Indian citizens who received Covishield shots. The matter has reached the Supreme Court, where a petitioner has sought directions to form a panel of medical experts to examine the vaccine's side effects.

During the pandemic, vaccine clinical trials were fast-tracked due to the urgent need to curb the virus' spread and save lives. This was driven by the overwhelming evidence that the benefits of vaccination exceeded the risks posed by the virus. However, the side effects, even if rare, have put a question mark over the safety of the AZ vaccine. The role of the regulatory authorities has also come under scrutiny. It is hoped that an in-depth inquiry will be carried out to pinpoint the lapses that imperilled the health of vaccine recipients. Fixing accountability and stressing the need for greater transparency should be the way forward.