Effectiveness of First Dose of COVID-19 Vaccines Against Hospital Admissions in Scotland: National Prospective Cohort Study of 5.4 Million People

Type Report Author Eleftheria Vasileiou Author Colin R. Simpson Author Chris Robertson Author Ting Shi Author Steven Kerr Author Utkarsh Agrawal Author Ashley Akbari Author Stuart Bedston Author Jillian Beggs Author Declan Bradley Author Antony Chuter Author Simon de Lusignan Author Annemarie Docherty Author David Ford Author Richard Hobbs Author Mark Joy Author Srinivasa Vittal Katikireddi Author James Marple Author Colin McCowan Author Dylan McGagh Author Jim McMenamin Author Emily Moore Author Josephine-L. K. Murray Author Jiafeng Pan Author Lewis Ritchie Author Syed Ahmar Shah Author Sarah Stock Author Fatemeh Torabi Author Ruby S. M. Tsang Author Rachael Wood Author Mark Woolhouse Author Aziz Sheikh URL https://papers.ssrn.com/abstract=3789264 Place Rochester, NY Date 19/02/2021 Extra DOI: 10.2139/ssrn.3789264 Institution Social Science Research Network Report Type SSRN Scholarly Paper Library Catalog papers.ssrn.com Language en Abstract Background: The BNT162b2 mRNA (Pfizer-BioNTech) and ChAdOx1 (Oxford-AstraZeneca) COVID-19 vaccines have demonstrated high efficacy against infection in phase 3 clinical trials and are now being used in national vaccination programmes in the UK and several other countries. There is an urgent need to study the ‘real-world’ effects of these vaccines. The aim of our study was to estimate the effectiveness of the first dose of these COVID-19 vaccines in preventing hospital admissions.Methods: We conducted a prospective cohort study using the Early Pandemic Evaluation and Enhanced Surveillance of COVID-19 (EAVE II) database comprising of linked vaccination, primary care, Real-Time Polymerase Chain Reaction (RT-PCR) testing, hospitalisation and mortality records for 5.4 million people in Scotland (covering ~99% of population). A time-dependent Cox model and Poisson regression models were fitted to estimate effectiveness against COVID-19 related hospitalisation (defined as 1- Adjusted Hazard Ratio) following the first dose of vaccine.Findings: The first dose of the BNT162b2 vaccine was associated with a vaccine effect of 85% (95% confidence interval [CI] 76 to 91) for COVID-19 related hospitalisation at 28-34 days post-vaccination. Vaccine effect at the same time interval for the ChAdOx1 vaccine was 94% (95% CI 73 to 99). Results of combined vaccine effect for prevention of COVID-19 related hospitalisation were comparable when restricting the analysis to those aged ≥80 years (81%; 95% CI 65 to 90 at 28-34 days post-vaccination).Interpretation: A single dose of the BNT162b2 mRNA and ChAdOx1 vaccines resulted in substantial reductions in the risk of COVID-19 related hospitalisation in Scotland.Funding: UK Research and Innovation (Medical Research Council); Research and Innovation Industrial Strategy Challenge Fund; Health Data Research UK.Conflict of Interest: AS is a member of the Scottish Government Chief Medical Officer’s COVID-19Advisory Group and the New and Emerging Respiratory Virus Threats (NERVTAG) Risk Stratification Subgroup. CRS declares funding from the MRC, NIHR, CSO and New Zealand Ministry for Business, Innovation and Employment and Health Research Council during the conduct of this study. SVK is co-chair of the Scottish Government’s Expert Reference Group on COVID-19 and ethnicity, is a member of the Scientific Advisory Group on Emergencies (SAGE) subgroup on ethnicity and acknowledges funding from a NRS Senior Clinical Fellowship, MRC and CSO. All other authors report no conflicts of interest.Ethical Approval: Approvals were obtained from the National Research Ethics Service Committee, Southeast Scotland 02 (reference number: 12/SS/0201) and Public Benefit and Privacy Panel for Health and Social Care (reference number: 1920-0279). Report Number ID 3789264 Short Title Effectiveness of First Dose of COVID-19 Vaccines Against Hospital Admissions in Scotland