Epidemiology of thrombotic thrombocytopenia syndrome in England [COVID-19]
Research type
Research Study
Full title
Epidemiology of thrombotic thrombocytopenia syndrome in integrated health data systems in England. Secondary data analysis using a cohort design.
IRAS ID
300924
Contact name
Simon de Lusignan
Contact email
Sponsor organisation
AstraZeneca
Duration of Study in the UK
1 years, 4 months, 30 days
Research summary
The AstraZeneca (AZ) COVID-19 vaccine has been widely deployed across the United Kingdom (UK) and, along with the Pfizer and Moderna vaccines, represents an important route out of the restrictions imposed as a result of the pandemic. In recent times, a number of reports have suggested that the AZ vaccine may be linked to a rare syndrome known as thrombotic thrombocytopenia syndrome (TTS). The syndrome consists of blood clots forming in unusual places coinciding with a reduced level of platelets in the bloodstream. Given that TTS has been reported in those receiving the AZ vaccine of all ages, with a possible increased rate in younger people, as well as the potential poor outcomes associated with TTS, it is of urgent public health importance to study this proposed association. The UK is in a unique position to perform such a study given the registration-based primary care system and the use of a unique identifier number that links primary care with secondary care data.
This retrospective cohort study aims to estimate the rate of TTS amongst those that have been vaccinated in the English population, to describe the characteristics of these patients, and to evaluate the association of TTS with certain risk factors. We will use the linkage of a number of primary and secondary care databases through NHS Digital’s Data Access Request Service (DARS) which should provide us with the largest dataset possible to achieve our objectives.
REC name
Yorkshire & The Humber - Bradford Leeds Research Ethics Committee
REC reference
21/YH/0126
Date of REC Opinion
3 Jun 2021
REC opinion
Favourable Opinion