AstraZeneca, in conjunction with Oxford University, developed the Covid-19 vaccine, Covishield, which has been linked to rare cases of blood clots and low platelet count. This condition is known as Thrombosis with Thrombocytopenia Syndrome (TTS). Despite initial assertions of safety, recent findings have led to the acknowledgement of these potential side effects by AstraZeneca, contrasting with their earlier stance.

The vaccine was administered widely across more than 150 countries, including significant distributions in the UK and India. Following the detection of adverse effects, there has been a class action lawsuit filed in the UK seeking compensation for those affected.

The World Health Organization has recognized the risks, yet maintains that the benefits of the vaccine continue to surpass the risks. The situation remains under observation as health experts and authorities evaluate the implications for ongoing Covid-19 vaccination efforts.