About DaC-VaP

Find out more about DaC-VaP's aims, how they will be achieved, and why they are important.

DaC-VaP stands for Data and Connectivity: COVID-19 Vaccine Pharmacovigilance 

It is an EAVE II associated project, that was led by Health Data Research UK in collaboration with the Office for National Statistics. 


As its name suggests, DaC-VaP's research focus was pharmacovigilance, meaning the science and activities relating to the detection, assessment, understanding, and prevention of any side effects of a vaccine or drug. 

DaC-VaP looked at how safe COVID-19 vaccines are, how well they worked in the general population, and how many people took a vaccine when they were offered it (vaccine uptake). 


In response to the pandemic, several COVID-19 vaccines have been developed. These include the Pfizer-BioNTech, Oxford-AstraZeneca, and Moderna vaccines, which are currently being used across the UK to protect people from the virus.  

To ensure these vaccines were effective (protecting people from getting COVID-19, or by reducing the risk of hospitalisation and death) the DaC-VaP team regulalry checked vast amounts of health data, that of millions of people who are registered with a general practitioner (GP) in the UK.  

It is crucial this is regular because some side effects may only be found once more people have been vaccinated, or may develop after a significant period of time. 

Our scientists first developed computer programs that first ran data on each of the four nations (England, Scotland, Wales and Northern Ireland) and then later combined them to give a UK-wide understanding of the vaccination programme. 

The computer programs also worked to link the medical information data from GP records, along with data from hospitals about their COVID-19 patients. 


DaC-VaP's research used the latest GP, hospital information, and COVID testing data from electronic medical records data in the UK. 

All records were edited to remove any details that could identify people, a process often reffered to as ‘pseudonymisation’ or ‘de-personalisation’. The health records without personal details (de-identified data) continue to be stored safely, and access is restricted to a small number of approved scientists in secure settings. 

For more information, visit the following webpages:

EAVE II data (Scotland)

Honest Broker Service (Northern Ireland)

Royal College of General Practitioners Research and Surveillance Centre (England)

SAILBANK Database (Wales)


The DaC-VaP team have contributed to publications that have informed the UK and Scottish Government responses to the pandemic, as well as our understanding of the effectiveness of COVID-19 vaccines. 

Our research has since gone on to influence future directions of COVID-19 research.

Our researchers engaged with a range of patient, public, community, professional and health policy groups who told us what questions were the most important to them when it came to vaccine research. These questions are now being investigated in the project DaC-VaP-2. For more information, visit:

DaC-VaP-2 research portal

Health Data Research UK DaC-VaP-2 project summary

Usher Institute DaC-VaP-2 study page

Our work is now being built upon by the Vaccine Breakthrough project, which looks to examine the effectiveness of currently administered or future approved vaccines by dose (mainly third or booster doses), viral variants and patient clinical and demographic characteristics. For more information, visit: 


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