Sociodemographic and Health Factors Affecting Uptake of Second Dose Covid-19 Vaccine in England: Retrospective Cohort Study Using Data from the National Primary Care Sentinel Surveillance Network (Oxford-Royal College of General Practitioners Clinical Informatics Digital Hub)

Abstract

Background: Two doses of COVID-19 vaccine offer greater protection than one dose. There are known disparities in COVID-19 outcomes and vaccine uptake. However, it is not known whether non-uptake of the second dose in people who have already received their first dose is predicted by differences in demographic characteristics and disease risk.<br><br>Methods: We conducted a retrospective cohort study using computerised medical record data from the nationally representative Oxford-Royal College of General Practitioners primary care sentinel cohort (N=7,952,861). Among adults who received at least one dose of Oxford-AstraZeneca ChAdOx1, mRNA Pfizer-BioNTech BNT162b2 or Moderna mRNA-1273 vaccines, we used univariable and multivariable logistic regressions to estimate the odds ratios (ORs) and adjusted ORs (aORs), and their 95% confidence intervals (95% CI), of second dose uptake.<br><br>Findings: In adults vaccinated with one dose (n=2,802,314), younger age, ethnic minorities, rurality (aOR=0.93 (95% CI 0.91-0.94)), East of England and the South West, current (0.59 (0.58-0.60)) and ex-smokers (0.93 (0.91-0.94)), severe mental illness (0.58 (0.56-0.60)) among other comorbidities, COVID-19 (0.57 (0.55-0.58)) or adverse events after their first dose, were associated with lower second dose uptake. Male sex (1.02 (1.00-1.03)), increasing socioeconomic status, asthma (1.04 (1.02-1.07)), and first dose mRNA vaccine (1.28 (1.27-1.30)) were associated with higher likelihood of second dose uptake.<br><br>Interpretation: Several demographic and risk groups at higher risk of adverse COVID-19 outcomes are less likely to receive second COVID-19 vaccination. Initiatives to increase vaccine uptake targeting people in sociodemographic groups and with comorbidities where interventions might have the greatest impact are needed.<br><br>Funding Information: This study was funded by UK Research and Innovation 460 (grant ref MC_PC_20029, MC_PC_20058).<br><br>Declaration of Interests: The authors declare that they have no conflict of interests.<br><br>Ethics Approval Statement: Ethical permission was obtained from the UK’s Health Research Authority (REC reference: 21/HRA/2786). Participation in DaCVaP was approved by the RCGP Joint Research and Surveillance Centre Committee (JRSCC).<br>