The Joint Committee on Vaccines and Immunisation (JCVI) and Expert Haematology Panel UK have advised that anyone with a history of blood clots are at no increased risk from the AstraZeneca Covid-19 vaccine. JCVI advise that adults aged 18 to 29-years-old who do not have underlying health conditions should be offered an alternative vaccine balancing risks and benefits. if a person has received their first dose of the AstraZeneca Covid-19 vaccine and did not develop vaccine-associated blood clots, then they are advised to attend for their second AstraZeneca vaccine when invited. Source : BBC