Blood Clot Risk After First AstraZeneca COVID-19 Shot Very Small - UK Study Shows

A large study into rare blood clots linked with AstraZeneca Plc's AZN COVID-19 vaccine found between one and three cases per million, and only after the first dose. The analysis sheds fresh light on the side effects of the shot.

A study published in the PLOS Medicine journal assessed health records of 46 million adults in England between December 2020 and March 2021 to assess the risk of clots in the month after vaccination with either the Pfizer Inc PFE - BioNTech SE BNTX vaccine or AstraZeneca-Oxford shot, compared with the unvaccinated.

No risk of major arterial and venous thrombotic events was found in those aged 70 or over with either of the vaccines.

While the risk of intracranial venous thrombosis (ICVT) following the AstraZeneca-Oxford vaccine was nearly double in those under 70, that was equal to between just one and three cases per million.

Related: AstraZeneca's COVID-19 Vaccine Booster Against Omicron, Delta - New Data Supports Use.

A second peer-reviewed British study also found that the risk of cerebral venous sinus thrombosis (CVST) in the four weeks after receiving the AstraZeneca-Oxford shot was roughly twice as high as before vaccination. However, it still implied that only one in four million people could have the side-effect.

The study assessed more than 11 million people in England, Scotland, and Wales.

Price Action: AZN shares are up 0.03% at $60.83 during the market session on the last check Wednesday.