Small Risk of Bleeding after AstraZeneca Vaccine

A new study of 5.4 million Scottish adults has discovered that there is a small increased risk of an autoimmune bleeding disorder after the first dose of the AstraZeneca/Oxford Covid-19 vaccine, even though a connecting link has not yet been established.

The study was led by University of Edinburgh scientists and was published today in Nature Medicine, measured the risk of bleeding-related events among 2.53 million people up to 27 days after the first dose of the AstraZeneca or Pfizer/BioNTech vaccine estimated from December 2020 to April 2021.Out of the 2.53 million people, more than 1.7 million have received the AstraZeneca vaccine, while on the other hand, about 800,000 people have received the Pfizer vaccine.

The risk of the autoimmune bleeding disorder, also known as immune thrombocytopenic purpura (ITP), was projected at 11 per 1 million first vaccine doses with the AstraZeneca vaccine. However, most people who developed ITP were not yet vaccinated, which the investigators said shows that ITP is not solely related to the vaccine. ITP, which is categorized by low platelet counts, can be asymptomatic or can cause slight bruising or excessive bleeding and long-term illness.

Although it is classically mild and can be treated according to the researchers. No deaths related to this bleeding disorder were informed among the vaccine recipients.The study findings also suggest that a very small increased risk can be thereof other AstraZeneca-linked major blood clot and bleeding events, although the rate was not higher than the rate of other vaccines.