COVID-19 vaccine uptake, effectiveness, and waning in 82,959 health care workers: A national prospective cohort study in Wales.

Background: While population estimates suggest high vaccine effectiveness against SARS-CoV-2 infection, the protection for health care workers, who are at higher risk of SARS-CoV-2 exposure, is less understood.
Methods: We conducted a national cohort study of health care workers in Wales (UK) from 7 December 2020 to 30 September 2021. We examined uptake of any COVID-19 vaccine, and the effectiveness of BNT162b2 mRNA (Pfizer-BioNTech) against polymerase chain reaction (PCR) confirmed SARS-CoV-2 infection. We used linked and routinely collected national-scale data within the SAIL Databank. Data were available on 82,959 health care workers in Wales, with exposure extending to 26 weeks after second doses.
Results: Overall vaccine uptake was high (90%), with most health care workers receiving theBNT162b2 vaccine (79%). Vaccine uptake differed by age, staff role, socioeconomic status; those aged 50-59 and 60+ years old were 1.6 times more likely to get vaccinated than those aged 16-29. Medical and dental staff, and Allied Health Practitioners were 1.5 and 1.1 times more likely to get vaccinated, compared to nursing and midwifery staff. The effectiveness of the BNT162b2 vaccine was found to be strong and consistent across the characteristics considered; 52% three to six weeks after first dose, 86% from two weeks after second dose, though this declined to 53% from 22 weeks after the second dose.
Conclusions: With some variation in rate of uptake, those who were vaccinated had a reduced risk of PCR-confirmed SARS-CoV-2 infection, compared to those unvaccinated. Second dose has provided stronger protection for longer than first dose but our study is consistent with waning from seven weeks onwards.
Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: AS is a member of the Scottish Government Chief Medical Officer’s COVID-19 Advisory Group,the New and Emerging Respiratory Virus Threats (NERVTAG) Risk Stratification Subgroupand amember of AstraZeneca’s Thrombotic Thrombocytopenic Task Force; all roles are unremunerated.CR is a member of the Scottish Government Chief Medical Officer’s COVID-19 Advisory Group, the Scientific Pandemic Influenza Group on Modelling and the Medicines & Healthcare products RegulatoryAgency’s Vaccine Benefit and Risk Working Group.DTB is employed by the Public Health Agency, Northern Ireland, and the Department of Health, Northern Ireland.MP is employed by the Vaccine Preventable Disease Programme at Public Health Wales and is involved in the COVID-19 vaccine roll out for Wales.SVK is co-chair of the Scottish Government’s Expert Reference Group on COVID-19 andethnicity, 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.RF is a member of is a member of the Scientific Advisory Group on Emergencies (SAGE) Social Care Working Group (SCWG).RO is a member of the National Institute for Health and Care Excellence (NICE) Technology Appraisal Committee (TAC) and has provided methodological advice outside of the submitted work toCogentiaHealthcare Consulting Ltd, F. Hoffmann-La Roche Ltd,the National Institute for Health and Care Excellence (NICE) Decision Support Unit, the University of Bristol, and the Association of the British Pharmaceutical Industry (ABPI).RAL is a member of the Welsh Government COVID19 Technical Advisory Group.All other authors have declared no competinginterests.
(Copyright © 2022. Published by Elsevier Ltd.)