Real World Evaluation of COVID-19 vaccines in England – a post authorisation effectiveness (PAES) and safety (PASS) study programme utilising population level data from the NHS Digital Trusted Research Environment

Patients

December 2024

Summary

AstraZeneca used a variety of patient databases, including GP records, vaccination history and hospital admissions reports, to evaluate real-world effectiveness and safety of one COVID-19 vaccine in England. 

About this study

Understanding how effective vaccinations have been within the wider population is central to guiding future vaccine development and influencing decision making. The study looked at population-level data for approximately 47 million individuals aged 16 and older, registered with GP practices in England. 

All, anonymous, patient data was accessed and analysed through a secure portal called the NHS Digital Trusted Research Environment (TRE). To protect patient privacy, data was redacted to ensure only essential figures are used for analysis.

Access to public patient data was crucial for this study as it enabled a comprehensive evaluation of COVID-19 vaccine effectiveness.

Data sources used:

• COVID-19 General Practice Extraction Service (GPES) data for Pandemic Planning and Research (GDPPR): data set containing all information relating to COVID-19
• Hospital Episode Statistics (HES): includes details on patient hospital admissions, outpatient appointments, and accident and emergency attendances at NHS hospitals in England
• COVID-19 Second Generation Surveillance System: collects data from COVID-19 tests done in NHS hospitals and community settings
• COVID-19 UK Testing Results: patient COVID-19 testing status and results
• COVID-19 Vaccination Status: which vaccine was administered, number of doses patient received and when
• COVID-19 Vaccination Adverse Reactions: whether patients suffered complications from vaccination
• Civil Registrations of Death (ONS Mortality): deaths of all individuals in UK

Benefits

The study used the data to understand vaccine effectiveness across one, two, and three doses, analysing variations by age, time between vaccinations, and underlying conditions. Second, the data was used to evaluate vaccine safety, focusing on the likelihood of adverse events or deaths and whether patients had any underlying health conditions. 

This access, safeguarded by strict privacy measures within the NHS Digital Trusted Research Environment, allowed AstraZeneca to determine the true effectiveness and safety of their vaccine in the wider population. In the future, the results from this study will help pharmaceutical companies, the Government and the NHS to make important decisions relating to vaccine development and rollout. 

Further information

Read the clinical study

Last modified: 13 January 2025

Last reviewed: 13 January 2025