Oxford/AstraZeneca COVID-19 Vaccine Effectiveness in England

Study Overview
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Brief Summary
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This is a retrospective cohort study to assess the real world effectiveness of the Oxford/AstraZeneca COVID-19 vaccine in England. The study is using linkage of the English national databases on COVID-19 vaccination, testing, medical records, hospitalization, and death.

Detailed Description
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The United Kingdom (UK) is one of the first countries that introduced a mass vaccination campaign for COVID-19 and vaccination of the adult population first focused on the oldest age groups, their carers and health care workers (JCVI, 2020). Three COVID-19 vaccines were licensed and are being used including the Moderna, the BioNTech/Pfizer, and the Oxford/AstraZeneca vaccines. Vaccination with the BioNTech/Pfizer vaccine started in December 2020 and the Oxford/AstraZeneca vaccine started in early January 2021. This study is to primarily assess the effectiveness of the Oxford/AstraZeneca COVID-19 vaccine. Given the known high efficacy of the mRNA vaccines in randomized controlled trials (RCTs) and real-world evidence studies, the study aims also to evaluate the vaccine effectiveness (VE) of other COVID-19 vaccines as a validation of the study's methods. On 16 September 2021 it was announced that Booster doses would be introduced in the UK to address vaccine waning and for groups with a suboptimal response. Little is known about health care resource utilisation (HCRU) and health care costs for those who have had COVID-19 or by individual clinical risk group. The RAVEN study is a retrospective cohort study to assess the real-world effectiveness of the Oxford/AstraZeneca COVID-19 vaccine in England. The study is using linkage of the English national databases on COVID-19 vaccination, testing, medical records, hospitalization, and death. Analyses will examine the effectiveness of one and two doses, and booster or other additional doses if applicable. This study's extension (October 2021) adds a more detailed exploration of VE in risk groups and an evaluation of the HCRU by people with COVID-19 compared with those who are vaccinated.

Official Title
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Real-world Effectiveness of the Oxford/AstraZeneca COVID-19 Vaccine in England. An Observational Retrospective Cohort Study Using Secondary Databases to Establish Effectiveness of the Oxford/AstraZeneca COVID-19 Vaccine in England.

Conditions
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Covid-19 Infection

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Eligible for any COVID-19 vaccination based on age at index date Have continuous data coverage for the COVID-19 infection datasets Have continuous data coverage in other linked databases for a minimum of 12 months prior to the index date Exclusion Criteria: • People with a history of COVID-19 infection (confirmed by reverse transcriptase polymerase chain reaction (RT-PCR) or not) prior index date

Ages Eligible for Study
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Minimum Age: 12 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Concurrent Controls<br> | |
| Vaccinated Cohort<br> | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence rate of COVID-19 related hospitalizations, COVID-19 related ICU admissions and COVID-19 related deaths |  | up to 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence rate of all-cause hospitalisations, all-cause ICU admissions and all-cause deaths |  | up to 12 months | 
| Incidence of positive SARS-CoV-2 test |  | up to 12 months | 
| Incidence of medically attended COVID-19 |  | up to 12 months | 
| Incidence of COVID-19 related emergency department visit |  | up to 12 months | 
| COVID-19 related healthcare resource utilisation | Number of primary care consultations, prescriptions, medical tests and investigations, hospital outpatient attendances and procedures, hospital emergency department attendances without admission, hospital admissions | up to 12 months | 
| Costs for COVID-19 related healthcare | Costs for primary care consultations, prescriptions, medical tests and investigations, hospital outpatient attendances and procedures, hospital emergency department attendances without admission, hospital admissions | up to 12 months |