The AstraZeneca COVID-19 vaccine is what is known as a ‘viral vectored vaccine’. Viral vectors, such as the genetically modified chimpanzee adenovirus contained in the AstraZeneca vaccine, come from a large family of viruses, some of which cause the common cold.
COVID-19 vaccines have not undergone the same degree of testing as regular vaccines. Instead, they were granted so-called ‘emergency use authorizations’ that bypass the requirement for full clinical trials to be carried out. In this situation it is almost inevitable that serious side effects can occur. The AstraZeneca vaccine has already been shown to cause deadly blood clots and a dangerous blood condition known as capillary leak syndrome, for example. Despite these risks, the company has received exemption from liability claims in most countries.
To learn more about the health risks of COVID-19 vaccines, read this article by Dr. Rath and Dr. Aleksandra Niedzwiecki.